JPH03196615A - Semiconductor manufacturing device - Google Patents

Abstract

PURPOSE:To prevent foreign matter from separating and readhering to a board by providing an exhaust pipe on the extension in the introductive direction of the flow of the gas introduced from the introduction port of the gas inside a reaction chamber, and making the diameter of the exhaust pipe lager than the diameter of the gas introduction port. CONSTITUTION:An exhaust pipe 6 is provided on the extension in the introductive direction of the gas introduced from the introduction port 2 inside a reaction chamber 1, and further the diameter of the opening of the exhaust pipe 6 is made lager than the diameter of the gas introduction port 2. That is, the gas flowing in the reaction chamber 1 from a minute pipe not only advances in the direction of introduction but also diffuses in the transverse direction and hits on the obstacle, whereby it produces turbulent flow. And the higher the speed is, the higher the flow speed expanding in the transverse direction and the speed of turbulent flow generated become, and the flow of gas at high speed is blown against the wall face of the reaction chamber or the parts. Hereby, the products which were adhering to the wall face, or the like, are separated by the blasting of gas at high speed, and they can be prevented from being readhering to a substrate 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to semiconductor manufacturing equipment that manufactures semiconductor devices by introducing gas into a reaction chamber. An example is shown in FIG. As shown in FIG. 5(a), there are parts such as an upper electrode 3 and a lower electrode 4 inside the reaction chamber 1 of the semiconductor manufacturing equipment, and a substrate 5 to be processed is placed inside the reaction chamber 1.
During processing, the reaction gas is introduced through the gas nozzle 2 and exhausted through the exhaust pipe 6 to maintain the pressure inside the reaction chamber 1 at an optimal pressure. In the manufacturing equipment (when the substrate 5 is placed inside the reaction chamber 1), unnecessary gases such as outside air may be mixed into the reaction. A series of operations such as introducing an inert gas and exhausting it together with the mixed gas is repeated.When the mixed gas in the reaction chamber 1 has been removed, the vacuum is drawn again, and the gas necessary for the reaction is pumped through the gas nozzle 2. The inert gas and reaction gas are introduced in conventional semiconductor manufacturing equipment.The inside of the reaction chamber is in a vacuum state, whereas the inside of the gas piping is at a pressure of about 3 atmospheres. Due to the difference, the gas flows into the reaction chamber 1 at a high speed.As shown in Figure 5(b), the gas that flows into the reaction chamber 1 at a high speed diffuses in a direction perpendicular to the direction of introduction, causing the gas to flow into the reaction chamber 1 inner wall and into the electrodes. 3.4 Problems to be solved by the invention that caused high-speed turbulent flow 7 due to contact with other parts As mentioned above, conventionally when introducing gas into the reaction chamber
The walls of the reaction chamber and the parts inside the reaction chamber are exposed to high-speed gas flow. Even if the products formed during etching are attached to the film, if the area where these deposits exist is exposed to a high-speed gas flow, some of the deposits will be removed from the wall or the surface of the part. The foreign matter peels off and floats inside the reaction chamber, and some of it adheres to the surface of the semiconductor substrate.If foreign matter adheres to the surface of the substrate, it becomes a source of defects in the semiconductor device. It is an object of the present invention to provide a semiconductor manufacturing apparatus that can prevent defects in semiconductor devices due to foreign matter peeling off and adhesion to the substrate surface due to the high-speed gas flow.

Means for Solving the Problems The present invention (Friend) In order to solve the above-mentioned problems, an exhaust pipe is installed on the extension line of the direction of introduction of the gas introduced from the gas inlet in the reaction chamber, and the opening diameter of the exhaust pipe is adjusted. The diameter of the gas inlet should be larger than the diameter of the gas inlet. Alternatively, a mechanism should be provided between the gas piping and the gas inlet into the reaction chamber to remove the flow of components of the gas flow in the direction perpendicular to the gas introduction direction. By introducing the gas into the micro-reaction chamber through a pipe with an inner diameter larger than that of the reactor, the flow rate of the gas around the walls of the reaction chamber and parts within the reaction chamber is slowed down. The gas flowing into the reaction chamber not only travels straight in the direction in which it is introduced, but also causes turbulent flow due to lateral diffusion and hitting obstacles. Speed of introduction of gas into the pipe ζ
This is determined by the difference in pressure between the reaction chamber and the pipe, and the gas must be blown in at a fairly high speed.If the introduction speed is high, the speed of the flow spreading laterally and the speed of the turbulence generated will also be high, resulting in a high-speed gas flow. It will be sprayed onto the walls and internal parts of the reaction chamber. The lateral direction of gas blown out from an inlet with an inner diameter large enough to cause products adhering to walls etc. to peel off due to high-speed gas blowing and re-adhering to the substrate, resulting in defects in semiconductor devices. Expansion to E-L
It spreads with the distance from the inlet, and if the distance is short, the spread becomes small.Generally, there are walls and parts in front of the gas blown out, and the gas flow hits these obstacles, causing turbulence in the surrounding area. By providing an exhaust pipe with a diameter close to or larger than the diameter of the gas flow that spreads forward from where the gas is blown out, it is possible to prevent the generation of turbulent flow due to collision of the gas flow with the wall surface, and There is no longer a high-speed flow of gas into the pipe, and only the low-speed gas flow due to diffusion comes into contact with walls or parts.Also, by installing a mechanism such as a muffler in the pipe that is introduced to remove the lateral flow of gas. , An even better effect may be to reduce the flow velocity of the gas blowing onto walls, etc.! friend
In addition to eliminating the turbulence or lateral flow mentioned above, this can be achieved by reducing the speed at which gas is introduced into the reaction chamber. The force that increases the difference t Since the degree of vacuum in the reaction chamber and the pressure in the piping are involved in the stability of the reaction, it is impossible to reduce the pressure difference below a certain limit 4. Other factors that determine the gas flow rate Even if the diameter of the pipe can be used, the flow velocity of gas flowing from a thin pipe to a thick pipe (which is inversely proportional to the square of the ratio of each inner diameter) will not decrease in the thick pipe. By introducing the gas into the reaction chamber after passing through the flow velocity relaxation section with an enlarged piping diameter, the initial velocity of the gas introduced into the reaction chamber is slowed down, and the flow velocity of the gas in contact with walls, etc. can also be slowed down. be.

Detailed explanation of the present invention using embodiment drawings (Example 1) A first embodiment of the present invention is shown in FIG. 1. FIG. 1 shows an example of a parallel plate type plasma semiconductor manufacturing apparatus. As shown in FIG. 1(a), even if the reaction chamber 1 has an upper electrode 3 and a lower electrode 4, and the substrate 5 is placed on the lower electrode 4, the inner diameter of the outlet is r1. An exhaust pipe 6 having an inner diameter r2 may be provided on the wall surface in the direction in which the gas flow exiting from the gas nozzle advances.
t, and the distance between the gas nozzle 2 and the exhaust pipe 6 is L(12). After the reaction chamber 1 with the above structure is evacuated, nitrogen or S i Ha, C1*, Na for reaction is added.
p.

CF4. When a gas such as 02 is introduced, the gas flow is as shown in FIG. Compared to the spread rl at the exit of the gas nozzle 2, the flow I5 travels a distance L
The length of the force has a spread proportional to the inner diameter r2 of the exhaust pipe
By making it larger, it is possible to suppress the turbulent flow that occurs when it collides with the wall surface to an unaffected level. However, most of the gas is exhausted through the exhaust pipe 6 through the force fork, but some gas is diffused and Since the reaction chamber is filled with a turbulent flow with a low flow rate, it does not affect the reaction (~ By having the structure of this example, it is possible to prevent the generation of high-speed turbulent flow or lateral flow that occurs when gas is introduced. (Embodiment 2) A second embodiment of the present invention is shown in FIG. 2. This example will also be explained using a parallel plate type plasma semiconductor manufacturing apparatus.Similar to Example 1, an exhaust pipe 6 having an inner diameter wider than that of the gas nozzle 2 is provided in the direction in which the gas flow 15 introduced from the gas nozzle 2 advances. By providing a muffler 16 between the gas pipe 13 and the gas nozzle 2, the component that spreads in the horizontal direction of the gas flow is removed.Thereby, the gas flow 15 introduced into the reaction chamber 1 is prevented from spreading in the horizontal direction. By using the structure of this embodiment, the spread of the gas flow 15 is reduced.The distance between the upper and lower electrodes and the inner diameter of the exhaust pipe 6 are reduced. Therefore, it is possible to reduce restrictions on the electrode spacing, the arrangement of internal parts, the installation of exhaust pipes, etc. (Embodiment 3) The third aspect of the present invention An example of this is shown in Fig. 3.This example shows the reaction chamber
An example of a semiconductor manufacturing apparatus using a parallel plate plasma having a structure in which a lower electrode 4 and an upper electrode 3 are provided and a substrate 5 is placed on the lower electrode is shown in FIG. 3(a). :
, a gas flow switching valve 19 which divides the gas inlet into an introduction gas nozzle 17 for introducing gas when the reaction chamber is in a vacuum state and a reaction gas nozzle 18 for introducing gas when a reaction occurs on the substrate 5; A mechanism for selecting the nozzle to be used is provided. In front of the gas nozzle 17 for gas introduction, a muffler 16 is installed in the same manner as in Example 2 to prevent the gas flow from spreading.
and a gas nozzle 17 for gas introduction, which can be selected by opening and closing a valve 22.
and the exhaust pipe 20 for introduction are installed so as to face each other, and the inner diameter of the exhaust pipe 20 for introduction is larger than the inner diameter of the nozzle 17.The gas nozzle 18 for reaction and the exhaust pipe 21 for reaction G1
The arrangement and size are such that the gas flow is stable and the reaction is uniform during the actual reaction.

In the apparatus having the above structure, after evacuating the inside of the reaction chamber 1, when introducing gas (see above), gas is introduced through the gas nozzle 17 for introduction and exhausted from the exhaust pipe 20 for introduction (Fig. 3). As shown in b), the gas flow 15 at this time is exhausted without causing turbulence or fast lateral flow. As shown in Figure (c), gas is introduced from the reaction gas nozzle 18 and the reaction exhaust pipe 21
The exhaust gas is slightly turbulent at this time Reaction chamber 1
The pressure inside the reactor has increased, and the gas introduction speed is slower than when it was first introduced, so there is no effect (- By using the structure of this example, it is possible to form the optimal gas flow for the reaction during the reaction, In addition, it is necessary to prevent the generation of dust due to turbulence, etc. when introducing gas.In addition, in this embodiment, the pressure inside the reaction chamber 1, where gas is introduced from the gas nozzle 18 for reaction, is increased to lower the pressure inside the gas pipe 8. By once lowering the speed, the speed of the turbulent flow that occurs becomes smaller (Example 4) A fourth example of the present invention is shown in FIG.
This is an example of a semiconductor manufacturing apparatus using a parallel plate plasma having a structure in which a lower electrode 4 and an upper electrode 3 are provided, and a substrate 5 is placed on the lower electrode, as shown in FIG. 4(a). A gas deceleration chamber 9 having an inner diameter larger than that of the gas pipe 8 can be provided between the pipe 8 and the reaction chamber 1. By using such a structure, the speed of the gas flow can be reduced as shown in Fig. 4(b). At the outlet of 8, it is V+, while at the inlet to reaction chamber 1, it is vt. 7) c, the ratio of the sizes of vt and Vl it
It is the reciprocal of the square of the ratio between the inner diameter of the gas pipe 8 and the inner diameter of the deceleration chamber 9, and even though vt is decelerated compared to vl, gas droplets introduced into the reaction chamber in this state spread laterally and cause turbulence. Even if the velocity decreases, deposits on the walls etc. will not be released. Effects of the Invention According to the invention An exhaust pipe is installed in the exhaust pipe, and the opening diameter of the exhaust pipe is larger than the diameter of the gas inlet, or the gas flow is perpendicular to the gas introduction direction between the gas pipe and the gas inlet into the reaction chamber. Introducing the gas into the reaction chamber by providing a mechanism to remove the flow of the component in the direction, or by introducing the gas into the reaction chamber through a tube with an inner diameter larger than the inner diameter of the gas piping. The flow rate of the gas around the chamber walls or parts inside the reaction chamber is lower than the flow rate in the gas introduction pipe.a This is to prevent foreign matter from peeling off from the reaction chamber walls or internal parts and re-adhering to the substrate.

[Brief explanation of drawings]

FIG. 1 shows a cross section of a parallel plate type plasma semiconductor manufacturing apparatus according to a first embodiment of the present invention. FIG. 2 shows a cross section of a parallel plate type plasma semiconductor manufacturing apparatus according to a second embodiment of the present invention. The cross section of the parallel plate type plasma semiconductor manufacturing apparatus shown in the third embodiment of the present invention is as shown in FIG.
The figure is a sectional view of a conventional parallel plate type plasma semiconductor manufacturing apparatus. 1...Reaction chamber 2...Gas nozzle/l,, 3...
- Upper electrode 4... Lower electrode 5... Group K 6...
Exhaust baffle 7...Do not disturb 8...Gas piping, 9...Gas deceleration chamber 13...Gas distribution 15...Gas t, 16.
...Muffler S 17...Gas nozzle 71 for gas introduction
．． , 18... Gas nozzle for reaction) k 19... Gas flow switching pulse 20... Exhaust pipe for gas introduction,
21...Exhaust pipe for reaction, 22...Valve, vl
...Gas first z we...Gas introduction speed It rl
... Gas nozzle inner arc r2 ... Exhaust pipe inner a

Claims (3)

[Claims] (1) In semiconductor manufacturing equipment that introduces gas into a reaction chamber, an exhaust pipe is installed on an extension line of the direction in which the gas is introduced from the gas inlet in the reaction chamber, and the opening diameter of the exhaust pipe is adjusted to the gas introduction direction. Semiconductor manufacturing equipment characterized by making the diameter larger than the diameter of the opening. (2) Between the gas piping and the gas introduction port into the reaction chamber,
2. The semiconductor manufacturing apparatus according to claim 1, further comprising a mechanism for removing a flow of a component of the gas flow in a direction perpendicular to the gas introduction direction. (3) A semiconductor manufacturing apparatus in which a gas is introduced into a reaction chamber, wherein the gas is introduced into the reaction chamber after passing through a pipe having an inner diameter larger than the inner diameter of a gas pipe.