JPH088206A - Infrared lamp annealing apparatus - Google Patents

Abstract

PURPOSE:To improve temperature uniformity in the surface of a wafer in an infrared lamp anneling apparatus, wherein the wafer is quickly heated and quickly cooled and undergoes annealing. CONSTITUTION:A plurality of infrared lamps 1 are arranged so as to surround the outer surface of a container 3. The infrared lamps, which are arranged in the ring shape, are rotated by a belt drive. The rotation is performed with the center of a semiconductor wafer 24 as an axis. The distance to the individual infrared lamp 1 and the position of the lamp 1 with respect to each part of the wafer 24 are instantaneously changed. The radiation intensity distribution of each lamp is offset. The amount of the infrared rays applied on each part of the wafer 24 is uniformly averaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared lamp annealing apparatus for heating a wafer with infrared rays in a gas atmosphere of N ₂ or the like to perform an annealing treatment such as activation of an ion-implanted layer or reflow of an insulating film. The present invention relates to a sheet-type infrared lamp annealing apparatus that performs annealing treatment on each sheet.

[0002]

2. Description of the Related Art Conventionally, a method of heating in an electric furnace has been adopted as an annealing method for activating an ion-implanted layer after ion implantation. This method has been carried out by heating the container to a target temperature with the lid of the container open, loading and unloading the wafer, and rapidly heating and cooling. However, in recent years, along with the demand for a shallow junction surface, it has become necessary to perform more rapid heating and cooling in a short time in order to suppress the generation of crystal defects. It has been difficult to obtain such conditions even by simply using an ordinary electric furnace having a large heat capacity. Therefore, various infrared lamp annealing apparatuses have been developed, focusing on the fact that the wafer is directly irradiated with infrared light and heated.

2A and 2B are a longitudinal sectional view and a lateral sectional view of an infrared lamp annealing apparatus showing a conventional example. As shown in FIG. 2, this infrared lamp annealing device has a lid 28 for opening and closing on one end side, a gas supply port 21 and a gas exhaust port 22 on the other end side, and is horizontally mounted quartz. Made of a container 23, three support bodies 27 which are housed in the container 23 and horizontally support the wafers 24 by point contact in order to reduce heat transfer loss, and a plurality of support bodies arranged vertically above and below the container 3. And an infrared lamp 25 of a book.

Although not shown in the drawing, the container 23
A cooling stage, a robot for transferring wafers, and the like are provided near the entrance and exit of the wafer 24, and a cassette for storing the unprocessed wafer and a processed cassette are arranged across the exit. Then, in order to prevent dust from adhering to the wafer, the circumference of the container 23 including the transfer system area is surrounded by one box body, and clean gas is down-flowed from the ULPA filter arranged on the top of the box body. It kept high cleanliness.

To activate the ion layer of the wafer by the infrared lamp annealing apparatus, first, a robot arm pulls out one unprocessed wafer from the cassette and places it on the support 27 of the container 23. Then, for example, nitrogen gas is introduced through the supply port 21 and discharged through the exhaust port 22 to perform gas replacement. Next, the infrared lamp 25 is turned on, and the wafer 24 is heated to 1000 ° C. And 10
After holding for about a second, the infrared lamp 25 is turned off, nitrogen gas is purged, and cooling is performed. When the temperature drops to a predetermined temperature, the robot arm grabs the wafer from the container 23 with the lid 28 opened and temporarily places it on the cooling stage, and the wafer activated by the robot arm is stored in the cassette.

As described above, this infrared lamp annealing apparatus can rapidly heat and cool, and continuously processes the wafers one by one without causing contamination or oxidation of the wafers, and has a high productivity. It was characterized by a single-panel device.

[0007]

In the above-mentioned conventional infrared lamp annealing apparatus, since the difference in the radiant intensity distribution peculiar to the infrared lamps and the relative distance between each infrared lamp and the wafer are fixed, the infrared rays in the center are fixed. The amount of light that is irradiated differs between the central portion of the wafer directly below the lamp and the peripheral portion of the wafer that is off the bottom. Due to the unevenness of the amount of light rays and the heating in a very short time, the temperature in the plane becomes non-uniform because the central portion of the wafer is high and the peripheral portion is low. This has the problem of causing crystal defects in the wafer.

An infrared lamp annealing apparatus for the purpose of improving the uniformity of the in-plane temperature distribution is disclosed in, for example, Japanese Patent Laid-Open No. 61-222634.
In this infrared lamp annealing device, a quartz container is placed upright, and a plurality of wafers are arranged diagonally above and below a support housed in the container. The wafer is heated by irradiating it with infrared rays from an infrared lamp.

However, although this infrared lamp annealing apparatus can obtain the temperature uniformity between wafers, it remains doubtful whether the temperature uniformity within the wafer surface can be obtained. What happens is that since one wafer is irradiated with infrared light at an angle, even if the optical path distance between the outer peripheral part and the central part of the wafer is different for infrared lamp light, and these optical paths are rotated even if the support is rotated. Distance does not change. As a result, the amount of light absorbed by infrared rays changes due to the difference in the optical path distance, which causes a difference in the amount of light emitted to the central portion and the peripheral portion of the wafer. That is, it is difficult to make the temperature within the wafer uniform as in the above case.

Goodbye, even if this technology is applied,
It is difficult to rotate the support of the above-mentioned infrared lamp annealing apparatus that supports the wafer by point contact. Also,
Even if a holding mechanism for securely holding the wafer is provided in order to prevent the wafer from falling due to rotation, heat is taken by the holding mechanism and the temperature of the wafer cannot be raised to a desired high temperature.

Therefore, an object of the present invention is to provide an infrared lamp annealing apparatus which can make the temperature distribution in the plane of a heated wafer uniform.

[0012]

A feature of the present invention is to provide a container having a gas supply port and a gas discharge port at one end and an opening at the other end, which is horizontally mounted and capable of transmitting light. A plurality of supports for horizontally supporting one wafer, which is a semiconductor substrate accommodated from the opening of the container, by point contact, a lid for closing the opening, and arranged so as to surround the outer periphery of the note. An infrared lamp annealing apparatus comprising: a plurality of infrared lamps; and a rotating mechanism that rotates the plurality of annular infrared lamps around the container.

It is also preferable that a cleaning chamber is provided adjacent to the opening of the container to keep clean air. Further, a connecting body that connects the lid and the plurality of supports is provided.

[0014]

The present invention will be described below with reference to the drawings.

1 (a) and 1 (b) are a partially cutaway side view and a top view of an infrared lamp annealing apparatus showing an embodiment of the present invention. This infrared lamp annealing device
As shown in FIG. 1, the gas supply port 21 and the gas discharge port 2
A transparent container 3 having two ends at one end and an opening at the other end and horizontally placed, and a plurality of supports 4 for horizontally supporting the wafers 24 accommodated from the openings of the container 3 by point contact.
A lid 8 for closing the opening, a plurality of infrared lamps 1 arranged so as to surround the outer periphery of the container 3, and a motor 11 for rotating the plurality of annular infrared lamps 1 around the container 3. The belt 10 has a rotating mechanism.

Further, as in the conventional case, a clean room surrounding the whole including the infrared lamp group and the transfer area may be used, but in the present invention, a small clean room is provided adjacent to the opening of the container 3 for the purpose of downsizing and energy saving. A chamber 5 is provided. And
In the clean room 5, air is blown from a blower (not shown) through the ULPA filter 5a into the clean room 5 through a duct, and the cleaned air is downflowed to the outside through the screen plate 7. .

Further, by providing a connecting portion 6 for connecting the lid 8 and the three support bodies 4, the wafer 24 is pulled out from the container 3 and the wafer 24 is taken out from the support body 4 or the wafer 24 to the support body 4. Makes it easier to place. In this way, the wafer 24 or the support 4 is placed in the container 3
It is possible to take out the wafer 24 by using a general-purpose pickup having a simple movement mechanism, without using a conventional robot that moves in a complicated manner and inserts an arm into the container 3 to take out a wafer and place a wafer. It has the advantage that it can be picked up or placed.

The lid 8 to which the support body 4 is attached via the connecting portion 6 is moved by the insertion / removal mechanism 12 which is a linear movement mechanism such as a hydraulic cylinder in which uneven feeding is unlikely to occur. While opening and closing the opening, the wafer 24 is pulled out from the container 3 into the cleaning chamber 5, or the wafer 24 is stored in the container 3.

The container 3 is made of quartz, and is sized so that one wafer 24 can be stored therein, and the shape of the container 3 is a circular tube for easy manufacture. Further, the infrared lamp 1 arranged in a ring shape is mounted by being passed over ring-shaped plates 13a and 13b fitted in a rotary bearing (not shown), and electrodes at both ends are contacts 9a embedded in the ring-shaped plates 13a and 13b. , 9b are electrically connected. The contacts 9a and 9b are in contact with the brushes 14a and 14b connected to the lamp power source 2 to supply power to all the infrared lamps 1.

On the other hand, the rotating mechanism of the infrared lamps 1 arranged in a ring shape is preferably driven by a belt which can rotate at high speed without causing vibration. As shown in FIG.
The belt driving mechanism is constructed by inserting the belt 10 fitted in the grooves of the outer shapes of 3a and 13b into pulleys 15a and 15b for connecting with the motor 11. Moreover, the number of rotations must be at least two during the irradiation of infrared light. For example,
If the irradiation time is 30 seconds, it is at least twice per minute.
That is, if the infrared lamp is rotated at a speed of 4 rpm or more, unevenness in the amount of light due to the distance of the infrared lamp from the wafer surface can be eliminated.

Next, the operation of this infrared lamp annealing apparatus will be described. First, the lid 8 is moved rearward by the insertion / removal mechanism 12, so that the support 4 is pulled out of the container 3 into the clean chamber 5. Then, one unprocessed wafer is taken out by a pickup (not shown) from a cassette (not shown) arranged on the upper side of the paper surface of FIG. Then, the wafer 24 is transferred onto the support 4 by a pickup. Next, the lid 8 is moved by the insertion / removal mechanism 12 to close the opening of the container 3 and the wafer 24 placed on the support 4 is stored in the container 3.

Next, by introducing nitrogen from the supply port 21 and discharging it from the exhaust port 22, the inside of the container 3 is replaced with nitrogen gas. Next, the infrared lamp 1 is turned on and the infrared lamp 1 is rotated. After irradiating the wafer 24 with infrared light for a predetermined time, the infrared lamp 1 is turned off and the rotation of the infrared lamp 1 is stopped. Then, the low temperature nitrogen gas is purged to cool the wafer 24. When the wafer 24 is cooled, the lid 8 is opened by the insertion / removal mechanism 12 and the wafer 24 is pulled out to the cleaning chamber 5. Next, FIG.
The wafer 24 on the support 4 is picked up from the lower side of the cleaning room 5 in FIG. Then, the wafer is transferred and stored in a processing cassette. In this way, the containers 3 are drawn one by one from the unprocessed cassette.
Then, the wafers are annealed and then housed one by one in a processing cassette, and the operation is repeated to process all the wafers in the cassette and the processing is completed.

The rotating mechanism for rotating the infrared lamp of the present invention and the inserting / removing mechanism for moving the lid to open / close the opening of the container are not limited to the mechanisms described in this embodiment.

[0024]

As described above, according to the present invention, a plurality of infrared lamps are arranged so as to surround the outer circumference of a transparent container for accommodating a support for supporting one wafer in a point contact manner. By rotating the group of arranged infrared lamps around the container, the position and distance from each infrared lamp corresponding to each part of the wafer can be changed instantaneously, so that the radiation intensity distribution of each infrared lamp is canceled out. As a result, the amount of infrared light irradiated to each part of the wafer is uniformly averaged. As a result, there is an effect that the temperature distribution on the wafer surface can be made uniform.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view and a top view of an infrared lamp annealing apparatus showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view and a lateral sectional view of an infrared lamp annealing apparatus showing a conventional example.

[Explanation of symbols]

 1,25 Infrared lamp 2 Lamp power source 3,23 Container 4,27 Support 5 Clean room 6 Connection 7 Screen plate 8, 28 Lid 9a, 9b Contact 10 Belt 11 Motor 12 Insertion / extraction mechanism 13a, 13b Ring plate 14a , 14b Brushes 15a, 15b Pulley 21 Supply port 22 Exhaust port 24 Wafer

Claims (4)

[Claims] 1. A container having a gas supply port and a gas discharge port at one end and an opening at the other end, which is horizontally mounted and can transmit light, and a semiconductor substrate accommodated through the opening of the container. A plurality of supports that horizontally support one wafer by point contact, a lid that closes the opening, a plurality of infrared lamps arranged so as to surround the outer periphery of the description, and arranged in a ring. An infrared lamp annealing apparatus, comprising: a rotating mechanism configured to rotate the plurality of infrared lamps around the container. 2. A cleaning chamber is provided adjacent to the opening of the container to keep clean air therein.
The infrared lamp annealing device described. 3. The infrared lamp annealing apparatus according to claim 1, further comprising a connector that connects the lid and the plurality of supports. 4. An insertion / removal mechanism for moving the lid together with the connecting body and the support to close an opening of the container or draw the container out of the container into the cleaning chamber. 3. The lamp annealing device according to item 3.