JPH09320974A - Heat treatment equipment - Google Patents

Abstract

(57) Abstract: A heat treatment apparatus capable of increasing the temperature while maintaining high uniformity of the in-plane temperature without lowering the throughput by optimizing the pitch of the object to be processed and the inner diameter of the heating object. I will provide a. A cylindrical processing container (4) for accommodating an object to be processed in a state where the object to be processed is supported in multiple stages at a predetermined pitch H, and
Heater 18 concentrically provided on the outer periphery of this processing container
In a heat treatment apparatus having: a radiant heat of a heating body directly or indirectly received from the heating body by the object to be treated, and a radiant heat received by the object to be treated being radiated from an adjacent object to be treated vertically adjacent to the object. Radiation transfer of three radiant heats, namely, body radiant heat and reflected self-radiant heat that the object to be processed receives by the adjacent object to be processed by the object to be processed and is radiated by the object to be processed. By analyzing using thermal analysis theory and form factor method,
The pitch of the object to be processed and the radius Rf of the heating element are set so that the in-plane temperature of the object to be processed becomes substantially uniform. As a result, the temperature is raised while maintaining the uniformity of the in-plane temperature of the object to be processed high.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a heat treatment apparatus.

[0002]

2. Description of the Related Art Generally, a diffusion layer, a silicon oxide film, a silicon nitride film, a polysilicon film or the like is formed on an object to be processed such as a semiconductor wafer or a glass substrate on which amorphous Si of LCD is formed. In this case, various heat treatment furnaces are used. As this heat treatment furnace,
For example, a so-called horizontal furnace, in which a large number of wafers arranged in the horizontal direction at equal intervals in a vertical direction are inserted into a horizontal furnace for heat treatment, has been the mainstream. In order to effectively use the space and to improve the uniform diffusion of process gas in the furnace, the furnace itself was made vertical and a large number of wafers were provided vertically at equal intervals while holding the wafer horizontally. So-called vertical furnaces, which are designed to perform heat treatment, have become mainstream.

At present, 8-inch wafers are mainly used, but 1G-bit fine processing is performed using wafers of a larger size, for example, 12-inch, in order to improve throughput and increase density. Have also been considered. Generally, in order to obtain chips with good product yield and uniform characteristics, the in-plane and inter-plane uniformity of the film thickness formed on the wafer is a major factor. Up to the process temperature of
It is necessary to raise the temperature while keeping the in-plane temperature distribution as uniform as possible. In addition, since the weight of the wafer increases as the diameter of the wafer increases, during heating, in addition to shear stress due to the weight of the wafer, thermal stress due to non-uniformity of the in-plane temperature is also applied, and microcracks are likely to occur. There is. Therefore, how to keep the temperature difference in the wafer surface small during heating is an important issue for suppressing microcracks.

In order to carry out uniform heating, it suffices to perform processing while keeping a considerable distance between the upper and lower wafers in the furnace, but it is not possible to keep the wafer interval in a dark state in consideration of throughput. Therefore, in designing the processing furnace, there are established design guidelines when determining the wafer spacing (pitch) and the inner diameter of the heating furnace that covers the processing container, which are major factors that determine the heating characteristics. Since it is not done, these are decided based on experience and intuition, and final trials and errors are repeated to decide the optimal numerical value.

[0005]

However, in the present day where the throughput and the large diameter of the wafer are advanced as described above, when designing the processing furnace for the large diameter, for example, the size of the 8-inch size which has been established to some extent is adopted. The design concept for processing a wafer cannot be directly applied to a processing furnace for processing a wafer having a larger diameter, for example, 12 inches. For example, as the wafer size increases, so does the heat capacity, and how the radiant heat radiated from the heating element to the wafer hits the wafer,
Complex elements such as heat transfer between wafers are entangled,
In order to design an optimum furnace that can raise the temperature to the process temperature while keeping the temperature difference in the wafer plane small, the trial and error as described above must be repeated.

In particular, recently, as the operating speed of an integrated circuit is increased, it is required to make the thermal diffusion depth of impurities shallower. In order to control this depth accurately and to improve the throughput as well. In addition, a so-called high-speed temperature raising / cooling treatment furnace has been developed in which the temperature of the wafer is rapidly raised to the process temperature and then rapidly lowered to the normal temperature after the treatment, but it is possible to maintain a large in-plane temperature uniformity. Caliber wafer,
For example, it becomes more difficult to design an optimal high-speed processing furnace capable of processing a 12-inch wafer.

[0007] The present invention focuses on the above problems,
It was created to solve this effectively. An object of the present invention is to provide a heat treatment apparatus capable of increasing the temperature while maintaining high in-plane temperature uniformity without decreasing throughput by optimizing the pitch of the object to be processed and the inner diameter of the heating element. Especially.

[0008]

In order to solve the above-mentioned problems, the present invention provides a cylindrical processing container for accommodating an object to be processed in a state in which a holder is supported in multiple stages at a predetermined pitch, In a heat treatment apparatus having a heating body concentrically provided on the outer periphery of this processing container, the radiant heat of the heating body directly or indirectly received from the heating body by the processing target body, and the processing target body above and below the radiant heat. The radiant heat of the object to be radiated and received from the adjacent adjacent object to be processed and the radiant heat of the object to be processed which is radiated from the object to be processed are reflected by the adjacent object to be processed and are thereby received by the object to be processed. By analyzing the three radiant heats, that is, the reflected self-radiant heat and the radiative heat transfer analysis theory and the method of form factor, the in-plane temperature of the object to be treated is made substantially uniform. Pitch and the heating It is obtained by constituting the radius to set.

With the above construction, it is possible to raise the temperature by heating while keeping the temperature difference within the surface of the object to be treated very small, and the uniformity of the in-plane temperature even in the steady state at the process temperature. Can be kept high. Regarding the actual numerical values, when the object to be processed is a wafer having a size of 8 inches, the pitch is within the range of 3 mm to 20 mm, and the radius of the heating element is within the range of 110 mm to 150 mm. When the object to be processed has a size of 12 inches, the pitch is in the range of 8 mm to 25 mm, and the radius of the heating element is in the range of 170 mm to 240 mm. In designing an actual heat treatment apparatus, radiant heat, that is, radiant heat of a heating body, radiant heat of an object to be treated, and reflected self-radiant heat are taken into consideration.
Based on these, the pitch of the object to be processed and the radius of the heating element such that the temperature difference in the surface of the object to be processed is always small and a uniform state is determined. When calculating the radiant heat, the view factor and the radiation heat transfer analysis theory which are determined by the geometrical arrangement state between the object to be processed and the heating object or the adjacent object to be processed are used. Further, when examining the temperature rise state of the object to be treated, it is preferable to consider the reflectance of the object to heat rays.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a heat treatment apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing a heat treatment apparatus of the present invention, and FIG. 2 is an enlarged view showing a positional relationship between an object to be processed and a heating body. In this embodiment, as a heat treatment apparatus, a batch type vertical heat treatment furnace for performing heat treatment such as oxidation diffusion of a semiconductor wafer will be described as an example.

This heat treatment furnace 2 is provided with a vertical cylindrical processing container 4 having a lower end opening made of a material that easily transmits radiant heat rays such as infrared rays and generates few impurities at high temperatures, for example, high purity quartz. In addition, a supporter, for example, a base plate 6 made of stainless steel is provided at the lower end opening of the processing container 4. The lower end of the processing container 4 is supported by, for example, a cylindrical manifold 7 made of stainless steel, which is held by the base plate 6, and the processing container 4 is vertically erected and supported in the longitudinal direction. There is. A furnace chamber 8 is formed in the processing container 4. In the furnace chamber 8 formed by the processing container 4, a quartz container 12 for accommodating an object to be treated, which is a holder placed on a quartz heat insulating cylinder 10, is provided so that it can be carried in and out. A large number of semiconductor wafers W to be processed are coaxially arranged and supported on the boat 12 in the horizontal direction at equal intervals in the vertical direction. As shown in FIG. 2, the wafer W is supported by placing the wafer peripheral portion on a support portion 16 provided in a convex shape on the boat support 14 at equal intervals with a predetermined pitch. Here, the pitch H between the wafers W
Alternatively, the heating element described below, that is, the radius Rf of the furnace body 18,
Since it is a major factor in performing in-plane soaking heating of the wafer, it is set to a value specified to maintain the uniformity of the in-plane temperature of the wafer using the radiation heat transfer analysis theory and view factor. It

A pipe 20 for introducing a process gas from the outside of the processing container 4 is provided in the furnace chamber 8, and a desired process for the semiconductor wafer W, such as an oxidizing process, a diffusing process, a film forming process, etc. Is feasible.
The heat insulation cylinder 10 is mounted on a flange cap 22 that acts as a lid of the processing container 4, and the flange cap 22 is attached to an elevator arm (not shown) and moves up and down. In this vertical movement, the heat retaining cylinder 10 and the boat 12 are moved up and down, and by the upward movement, the opening of the manifold 7 at the lower end of the processing container 4, that is, the boat insertion port 4A can be sealed by the cap 22. . Furthermore, the heat insulating cylinder 10 is configured to be rotatable by transmitting the rotation of a motor (not shown) to the rotary shaft via the belt 24. On the other hand, on the outer periphery of the processing container 4, a cylindrical heating body 18 is concentrically provided so as to cover the container. Here, the furnace body constitutes a heating body 18, and the furnace body comprises, for example, a resistance heating body 26 made of molybdenum disilicide or the like, a heat insulating material 28 for blocking heat transferred to the outside, and The outer shell 30 is made of, for example, stainless and covers the heat insulating material 28.
A furnace body structure may be provided in which a cylindrical quartz soaking tube coated with, for example, SiC is provided inside the resistance heating element 26. In this case, the structure including this soaking tube becomes a heating body.

Further, the manifold 7 is formed with an insertion hole through which the lower end of the pipe 20 is inserted, and the lower end of the pipe 20 is inserted through the through hole to form a gas introduction port 32. An exhaust port 34 for exhausting the atmosphere in the processing container 4 is formed therein. In particular, in the present embodiment, for example, when processing an 8-inch size wafer, the radius Rf of the heating element is 110 mm to 15 mm.
The wafer pitch (pitch of the supporting portion) H is set within the range of 0 mm, and is set within the range of 3 mm to 20 mm.
Radius Rf when processing inch size wafers
Is set in the range of 170 mm to 240 mm, and the wafer pitch H is set in the range of 8 mm to 25 mm so as to maintain high in-plane uniformity of the wafer at the time of temperature rise and steady state as described above. It is set.

Next, the operation will be described. First, when the heat treatment, for example, the oxidation treatment of the wafer W is performed, the boat 12 holding a large number of 8- or 12-inch semiconductor wafers is carried into the furnace chamber 8. Then, when the inside of the furnace chamber 8 is set in an airtight state, heating by the heating resistor 26 is performed. The wafer may be loaded into the furnace chamber 8 in advance to a temperature at which the growth of an oxide film is suppressed, for example, a set temperature of 600 ° C. or lower, and then the boat 12 may be loaded. Radiant heat from the heating resistor 26 directly passes through the processing container 4 and enters the semiconductor wafer W in the furnace chamber 8.

Next, when the wafer reaches the process temperature, a process gas corresponding to the heat treatment is introduced into the furnace chamber 8 through the process gas pipe 20, and the heat treatment is performed for a predetermined time. During this time, the atmosphere in the furnace chamber 8 is exhausted from the exhaust port 34, and the inside is maintained at a predetermined process pressure to perform the desired heat treatment.

By the way, as described above, when the temperature of the wafer is raised, how small the temperature difference in the wafer surface is kept while heating is that the film thickness and the like are kept uniform and the electrical characteristics of the semiconductor circuit are kept. Is to be maintained uniformly and the throughput is improved, which is a big problem. Regarding the heat distribution in the wafer surface at the time of temperature rise, the pitch H of the wafers vertically adjacent to each other and the radius Rf of the heating body 18 act particularly, and how to set these values in the design of the processing furnace. Whether or not it will be a big point. In particular, a new high-speed heat treatment furnace that can increase and decrease the temperature of wafers at high speed,
How to determine the size of this heat treatment furnace in the case of a large processing furnace that heats a 12-inch wafer that is expected to become the mainstream from now on and makes a chip with a large capacity of 1 Gbit It is important to do it.

When considering heating of the wafer, the present inventor uses not only the radiant heat directly or indirectly received by the wafer from the heating body, that is, the radiant heat of the heating body, but also the wafer above and below the wafer according to the radiation heat transfer analysis theory. Radiant heat radiated and received from another adjacent wafer, that is, radiant heat of the object to be processed and radiant heat of itself radiated from the wafer itself, which is reflected by another adjacent wafer and received again by itself, that is, reflected self We found that radiant heat should also be considered. FIG. 3 shows a model of the situation at this time. That is, reference numeral W1 is a wafer of interest as a heating target, and wafer W2 is an adjacent wafer that affects the heating of the wafer W1. Actually, an adjacent wafer is also arranged below the wafer W1, but the description of the lower wafer is omitted here for simplification of description.

First, considering the radiant heat incident on the specific area 36 of the wafer W1 based on the radiation heat transfer analysis theory, the radiant heat of the heating body coming into the area 36 directly or indirectly from the heating body (furnace wall) 18. 38 and the adjacent wafer W
2 radiant heat 42 of the object to be processed which is radiated from a certain area 40 of the wafer 2 and is received by the specific area 36 and radiant heat radiated from an area 43 of the own wafer W1 hits the adjacent wafer W2 and is reflected by the adjacent wafer W2 again. Reflected self-radiant heat 44 entering W1 enters. Radiant heat of the heating element 3
8 is not only the direct radiant heat 38A from the heating body 18,
It also includes reflected radiant heat 38B in which the radiant heat from the heating body 18 is reflected by another object, for example, the adjacent wafer W2, and is incident on the own wafer W1. And, in the reflected radiant heat 38B,
Not only once, but also once to infinitely many times, all the reflected radiant heat that is incident after being reflected from another portion or the wafer W1 of itself.

As described above, the temperature of the wafer W1 is gradually raised by the above three radiant heats.
It is only necessary to obtain a condition that minimizes the temperature difference within the wafer when the two radiant heats are combined and taken into consideration. When considering heat transfer due to radiation between two or more solid surfaces, the view factor F (View Factor Defi) determined by the shape of the geometrical arrangement of the two surfaces.
It is already known that the calculation of the amount of heat exchanged is facilitated by using the N. The amount of radiant heat exchange between two objects will be described using the schematic diagram shown in FIG.

In FIG. 4, dAi and dAj are black body 2 surface A
The small elements on i and Aj, and s are the distances between them.
Further, the angles formed by the normals ni, nj in dAi, dAj and the s direction are φi, φj, respectively. Assuming that the heat flow dQi comes out of dAi and is absorbed by dAj, dQi is given by the following equation 1.

[0021]

[Equation 1]

Where σ is a Boltzmann coefficient. Similarly, the heat flow dQj that emanates from dAj and is absorbed by dAi is given by the following equation 2.

[0023]

[Equation 2]

The radiant heat is proportional to the fourth power of the absolute temperature of the object. Therefore, the heat flow dQ in which the radiative heat is exchanged between dAi and dAj is given by the equation 3.

[0025]

(Equation 3)

Here, the form factor F is defined by the following equation 4.

[0027]

(Equation 4)

Note that Fdidj is a view factor of the surface dAi with respect to the surface dAj. Therefore, dQ is as shown in Equation 5.

[0029]

(Equation 5)

When this is integrated, the net outflow heat flow Qo from the surface Ai finally becomes as shown in the equation (6).

[0031]

(Equation 6)

When the surfaces Ai and Aj are gray bodies,
Introducing emissivity εi and εj, respectively, Qo becomes as shown in Equation 7.

[0033]

(Equation 7)

Here, the above heat flow is shown in FIG.
In the model as shown in FIG. 1, before that, the own wafer W1 and the above-mentioned object that generates the three radiant heat, that is, the heating body 18, the adjacent wafer W2, and the own wafer W1 (others by reflection) (Because it can be regarded as an object of the above), a rough form factor between The prediction of the result at that time is shown in FIG. On the horizontal axis of FIG. 5, the center of the wafer W1 is located at the center, and the horizontal scale indicates the distance from the center. In calculating the shape factor, the pitch H and the radius Rf shown in FIG.

Here, as an example, in the case of a 12-inch wafer size, the wafer pitch is set to 16 mm and the distance between the wafer and the heating body is set to 60 mm. Therefore, the heating element radius is set to 210 mm. As is clear from the graph shown in FIG. 5, the reason why the view factor for the adjacent wafer is larger than that for the own wafer W1 is that the radiant heat from the own wafer is reflected by the adjacent wafer and then enters the adjacent wafer. This is because the substantial distance is increased accordingly. That is, this is equivalent to the wafer being located on the opposite side with the adjacent wafer as the center of line symmetry. Further, the view factor for the heating element 18 is considerably low because the positional relationship between the wafer W1 of its own and the heating element 18 is orthogonal.

If the total sum of the amount of radiant heat actually received by the wafer W1 of its own is obtained by prediction based on the above-described form factor, the graph shown in FIG. 6 seems to be obtained. That is, in FIG. 6, the graph indicated by the alternate long and short dash line shows the radiant heat that the wafer W of its own receives in each area on its surface, and the wafer pitch H and radius Rf at which this line becomes a straight line in a substantially horizontal direction. It suffices to determine (see FIG. 2), which makes it possible to design a furnace body having a very small temperature difference within the wafer surface when the temperature of the wafer is raised.

In the graph shown in FIG. 6, the amount of radiant heat from the heating element 18 is larger than the others, while the temperature of the heating element itself is extremely high in advance when the temperature rises. This is because the temperature of the wafer itself is considerably lower than that of the heating body. When obtaining the graph shown in FIG. 6, the reflectance of the wafer itself against radiant heat is also taken into consideration. Furthermore, since the transmittance of the wafer to the heat ray also changes depending on the temperature, if a graph is obtained by taking into account that amount, a more optimal processing furnace can be designed.

Now, the process of calculating each form factor when the above-described heat flow is applied to the geometrical model of the actual heating furnace will be described in detail. Inside the furnace, there are a plurality of wafers, a furnace wall as a heating element heated by a heater such as a resistance heating element, and a wafer supporting jig. Since the wafer supporting jig is small in size and exists only locally, it is not taken into consideration here. The overall view factor is the sum of exchange radiation between wafers and radiation from the furnace wall to the wafer. First, consider the view factor between wafers. FIG. 7 is a diagram showing a model when considering the form factor of wafers. Two wafers A and A ₂ are arranged facing each other in parallel, and the wafer is considered to be a reflector and a radiator. With the wafer A ₂ as a reference, the minute element dA,
When the solid angle G is calculated for dA ₂ , the following formula 8 is obtained.

[0039]

(Equation 8)

Here, H is the pitch between the wafers, r, r '.
Is the distance from the wafer center Z to the minute elements dA and dA ₂ , the angle between the wafer center and the minute elements dA and dA ₂ on the plane, and φ is the minute element dA to the minute element dA _2.
It is the angle with the vertical direction when you look at. Since the form factor is obtained by integrating the solid angle, the above formula is integrated with respect to dθ from 0 to 2π to obtain a temporary form factor f given by the following Expression 9.

[0041]

[Equation 9]

Further, in order to obtain the form factor for the entire surface of the wafer, the above formula 9 is integrated with respect to r in order to integrate it in the radial direction of the wafer, and the provisional form factor fo of the zero-order reflection given by formula 10 is obtained. .

[0043]

(Equation 10)

In reality, it is considered that the reflection is repeated n times between the wafers, and the reflected light results in the n-th radiation.
The tentative form factor fn of the nth-order reflection is as in the following Expression 11.

[0045]

[Equation 11]

Since the radiant light is weakened by the reflectance for each reflection, the final final form factor _Fwaf between the wafers as the reflectance λ is _given by the following formula 12.

[0047]

(Equation 12)

Next, the view factor between the wafer row and the furnace wall is determined. FIG. 8 shows a case where _two wafers A and A ₂ are in the furnace, and the wall surface of the heating body 18 which can be seen from the lower wafer A ₂ in the figure as a reference, that is, the area of the furnace wall is It depends on the distance to the wafer A, that is, the pitch H. Therefore, the height of the furnace wall viewed from the wafer is limited. Assuming that the minute area dA ₂ is on the x-axis as in the case shown in FIG. 7, the coordinates of the center of this minute area are located at the point a (r, 0, 0). Here, r is the distance on the x-axis from the center O to the point a. Although not shown in the figure, the y axis is a direction orthogonal to the x axis on the wafer plane, and the z axis is a direction orthogonal to the x and y axes, that is, the vertical direction in the figure. When this point a is looking up at the furnace wall, the upper limit of its height is a point b (x, where a straight line connecting the point a and the edge c of the upper wafer A intersects the furnace wall.
y, z). The equation of this straight line l is as in the following Expression 13.

[0049]

(Equation 13)

It is to be noted that θ is an angle formed by a straight line connecting a center θ with a point where a perpendicular line drawn from the point b on a plane of the wafer A ₂ intersects with the straight line extending from the center O to the point a. Where point b
Is on the furnace wall surface on the circumference having a radius of Rf, and is constrained by the following equation.

[0051]

[Equation 14]

Therefore, from the above equation 13, x and y are given by the following equations 15 and 16.

[0053]

(Equation 15)

[0054]

(Equation 16)

From the above equations 14, 15 and 16, the height h of the point b is as shown in the following equation 17.

[0056]

[Equation 17]

Therefore, the form factor F _fur has θ of 0 to 2π.
By integrating up to, the following equation 18 is obtained.

[0058]

(Equation 18)

Therefore, the overall form factor of the wafers to be considered in the heat treatment furnace is the form factor F _waf between the wafers shown by the formula 12 and the form factor F from the furnace wall shown by the formula 18.
_{It is} the sum of _fur . Moreover, each radiating surface has an emissivity determined by the material and its surface state, and if the emissivity of the wafer is ε _waf and the _{emissivity of} the furnace wall is ε _fur , the micro area dA ₂ on the actual wafer surface is The form factor F _total is as in the following _Expression 19.

[0060]

[Equation 19]

As described above, the view factor in the furnace can be obtained as a theoretical formula.
The inch wafer was numerically analyzed and simulated. The results at this time are shown in FIGS.
9 to 13 show simulation results for an 8-inch size wafer, and FIGS. 14 to 18 show simulation results for a 12-inch size wafer. The horizontal axis shows the radius from the center of the wafer, and the vertical axis shows the view factor in consideration of the emissivity, which corresponds to the actual temperature.

In the case of an 8-inch wafer, FIG. 9 to FIG.
In each graph shown in 3, the wafer pitch H is set to 3 m.
It shows the result when changing to m, 10 mm, 20 mm, 30 mm, and when the radius Rf of the heating element is changed from 110 mm to 150 mm in accordance with the transition from FIG. 9 to FIG. 13, H = 3 mm to H = It was found that the characteristic curve was substantially flat within the range of 20 mm, and the in-plane temperature of the wafer was substantially uniform within this range, which showed good results. In particular, when the radius Rf of the heating element is set to 130 mm as shown in FIG. 11, the pitch H is 3 mm to 20 m.
It has been found that the best results are obtained when set within the range of m.

In the case of a 12-inch wafer, the wafer pitch H is set to 8 in each graph shown in FIGS.
It shows the result when changing to mm, 15 mm, 25 mm, 50 mm, and when the radius Rf of the heating element is changed from 170 mm to 240 mm according to the transition from FIG. 14 to FIG. 18, all of H = 8 mm to 25 mm It was found that the characteristic curve was substantially flat within the range, and the in-plane temperature of the wafer was substantially uniform within this range, and good results were shown. In particular, when the radius Rf of the heating element is set to 200 mm as shown in FIG. 16, the pitch H is 8 mm to 25 mm.
It was found that the best result was obtained when the value was set within the range. In addition, in the above-mentioned embodiment, the heat treatment apparatus for performing the oxidation treatment is described as an example, but the present invention is not limited to this, and the present invention can be applied to any heat treatment apparatus as long as it is a vertical batch treatment furnace. is there.

[0064]

As described above, according to the heat treatment apparatus of the present invention, the following excellent operational effects can be exhibited. When the temperature of the object to be processed is raised, it is possible to easily design a heat treatment apparatus capable of raising the temperature to the process temperature while keeping the temperature difference in the plane of the object to be processed to be a substantially uniform state without decreasing the throughput. be able to. Therefore, the time and cost required for the optimum design can be largely eliminated. Further, with the heat treatment apparatus designed in this way, it is possible to perform a predetermined thermal process while maintaining high in-plane temperature uniformity of the object to be treated.

[Brief description of drawings]

FIG. 1 is a sectional view showing a heat treatment apparatus.

FIG. 2 is an enlarged view showing an arrangement relationship between an object to be processed and a heating body.

FIG. 3 is a diagram for explaining radiant heat to be considered.

FIG. 4 is a diagram showing a model for explaining a radiant heat exchange amount between two objects.

FIG. 5 is a schematic graph showing a simulation result of a view factor of each member that contributes to heating of an object to be processed.

FIG. 6 is a schematic graph showing the amount of radiant heat that the object to be processed actually receives from each member.

FIG. 7 is a diagram showing a model for explaining a view factor between wafers.

FIG. 8 is a diagram showing a model for explaining a view factor between a wafer and a heating body.

FIG. 9 is a graph showing a simulation result of an 8-inch size wafer.

FIG. 10 is a graph showing a simulation result of an 8-inch size wafer.

FIG. 11 is a graph showing a simulation result of an 8-inch size wafer.

FIG. 12 is a graph showing a simulation result of an 8-inch size wafer.

FIG. 13 is a graph showing a simulation result of an 8-inch size wafer.

FIG. 14 is a graph showing a simulation result of a 12-inch size wafer.

FIG. 15 is a graph showing a simulation result of a 12-inch size wafer.

FIG. 16 is a graph showing a simulation result of a 12-inch size wafer.

FIG. 17 is a graph showing a simulation result of a 12-inch size wafer.

FIG. 18 is a graph showing a simulation result of a 12-inch size wafer.

[Explanation of symbols]

 2 Heat treatment furnace 4 Processing container 12 Processing object storage boat (holding body) 18 Furnace body (heating body) 26 Resistance heating element 38 Heating body radiant heat 42 Processing body radiant heat 44 Reflected self-radiation heat W Semiconductor wafer (processing body) W1 Self Wafer W2 Adjacent wafer

Claims (6)

[Claims] 1. A heat treatment comprising a cylindrical processing container for accommodating an object to be processed supported by a holding body in multiple stages at a predetermined pitch, and a heating body concentrically provided on the outer periphery of the processing container. In the device, the radiant heat of the heating body to be directly or indirectly received from the heating body by the body to be processed, and the radiant heat of the body to be processed which is radiated from the adjacent body to be processed vertically adjacent to the body to be processed. , The radiation heat transfer analysis theory of three radiation heats, namely, the reflected self-radiation heat that the object to be processed receives by the adjacent object to be processed by the radiation heat of itself emitted from the object to be processed. And by using a view factor method, the pitch of the object to be processed and the radius of the heating element are set so that the in-plane temperature of the object to be processed is substantially uniform. Heat treatment to apparatus. 2. The heat treatment apparatus according to claim 1, wherein the radiant heat from the heating body is a sum of radiant heat from the radiant heat from the heating body that reaches the object to be processed after being reflected up to an infinite number of times. . 3. The heat treatment apparatus according to claim 1, wherein each radiant heat is obtained by using a radiation heat transfer analysis theory and a form factor. 4. When setting the pitch and the radius,
The heat treatment apparatus according to claim 1, wherein the heat treatment apparatus is configured to take into consideration the reflectance of the object to be processed. 5. When the diameter of the object is 8 inches, the object pitch is 3 mm.
To 20 mm, and the radius of the heating element is 1
The heat treatment apparatus according to claim 1, wherein the heat treatment apparatus is in the range of 10 mm to 150 mm. 6. When the object to be processed has a diameter of 12 inches, the object to be processed has a pitch of 8
The heat treatment apparatus according to any one of claims 1 to 4, wherein the heating body has a radius of 170 mm to 240 mm and a radius of the heating body is 170 mm to 240 mm.