JP2004134631A - Lamp heat treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lamp heat treatment device which eliminates the difference in the thickness between an oxide film on a first wafer and an oxide film on each of a second and the subsequent wafers, and at the same time prevents warpage or breakage of the first wafer in a continuous processing. <P>SOLUTION: The lamp heat treatment device is provided with a metal chamber which is provided therein with a lamp unit consisting such as a tungsten halogen lamp and the like for serving as a lamp light source, a quartz plate for defining the lamp unit, a support ring made of silicon carbide for horizontally supporting a wafer, a rotary cylinder for mounting the support ring, radiation thermometers disposed at the rear of the wafer, and a cooling gas line or a cooling ring made of silicon carbide for cooling the support ring alone in a short time. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lamp heat treatment apparatus used for oxidizing or heat treating a semiconductor wafer in a semiconductor device manufacturing process.
[0002]
[Prior art]
In recent years, a lamp heat treatment apparatus capable of rapid heating and rapid cooling when oxidizing a semiconductor wafer has been used. A conventional heat treatment apparatus is an apparatus that heats a semiconductor wafer placed in a metal chamber by irradiating light such as a tungsten halogen lamp, and the chamber includes a plurality of process gas sources required according to a processing step. They are connected (for example, see Patent Document 1).
[0003]
Such a conventional lamp heat treatment apparatus will be described with reference to the drawings. FIG. 2 is a schematic view of a conventional lamp heat treatment apparatus. The conventional apparatus has a metal chamber 201 as shown in FIG. 2, a lamp unit 202 including a tungsten halogen lamp or the like serving as a lamp light source, a quartz plate 203 partitioning the lamp unit 202, A silicon carbide support ring 205 for horizontally supporting the wafer 204, a rotating cylinder 206 for mounting and rotating the silicon carbide support ring 205, and a radiation thermometer 207 on the back side of the wafer 204 are provided.
[0004]
The chamber 201 is provided with a gas supply line 208 for supplying a process gas into the chamber 201 and a gas exhaust line 209 for discharging a processing gas. The rotation cylinder 206 is rotated by a driving mechanism, and can rotate the wafer 204 in the chamber 201 at 90 rotations / minute. The radiation thermometer 207 receives radiation from the back surface of the wafer 204, converts the temperature to a temperature, and measures the temperature. In order to read the in-plane temperature of the wafer 204, a plurality of radiation thermometers are placed at positions from the center of the wafer 204 to the back surface on the outer periphery.
[0005]
When the wafer 204 is heat-treated using a conventional lamp heat treatment apparatus having such a structure, the wafer 204 is carried into the chamber 201 and placed on the silicon carbide support ring 205. Next, a desired process gas is supplied from the gas supply line 208, and the heat treatment is performed while the lamp unit 202 is turned on and the wafer 204 is rotated.
[0006]
In the case of performing the continuous process, a preheat process of turning on the lamp unit 202 for 5 to 10 minutes without the wafer 204 for eliminating the difference in the oxide film thickness between the first and second sheets is performed. After that, the first wafer 204 is loaded into the chamber 201, and the first wafer 204 is subjected to a heat treatment. After the heat treatment of the first wafer 204 is completed and carried out, the second wafer 204 is carried into the chamber 201 and heat treated. After the third and subsequent wafers have been processed and unloaded, the next wafer 204 is loaded into the chamber 201 and heat-treated.
[0007]
[Patent Document 1]
JP-A-5-13355
[Problems to be solved by the invention]
In the conventional lamp heat treatment apparatus, if a preheating process is provided for 5 to 10 minutes before the first sheet in the continuous processing and the inside of the chamber is not heated, a difference occurs in the oxide film thickness between the first and second sheets. Only the first sheet becomes thinner.
[0009]
However, when the preheat treatment is performed, the temperature of the silicon carbide support ring excessively rises, and a temperature difference of 100 ° C. or more occurs between the center and the outer periphery of the wafer when the first wafer is loaded. Occurs.
[0010]
After the preheat treatment, if a long natural cooling time is provided so that the temperature of the silicon carbide support ring is sufficiently lowered, the temperature difference between the center and the outer periphery of the wafer becomes 100 ° C. or less, and the wafer jumps and cracks. However, since the inside of the chamber cools, a difference occurs between the oxide film thicknesses of the first and second films, and only the first film becomes thin.
[0011]
In other words, in the conventional lamp heat treatment apparatus, there is a trade-off between eliminating the difference in oxide film thickness between the first and second wafers in continuous processing and preventing the first wafer from jumping or cracking. , Both can not be satisfied.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, a lamp heat treatment apparatus according to the present invention includes a heating lamp unit provided at an upper part in a chamber, a radiation thermometer provided at a lower part in the chamber, and a lamp thermometer provided in the chamber. It is characterized by comprising a support ring for mounting a wafer, a rotary cylinder for mounting and rotating the support ring, and a cooling mechanism for cooling the support ring.
[0013]
With this configuration, in the continuous process, the chamber is not cooled before the first wafer after the preheating process is loaded, and only the support ring can be cooled in a short time. Therefore, when the first wafer is loaded, the temperature difference between the center and the outer periphery of the wafer is suppressed to 100 ° C. or less, and it is possible to prevent the wafer from jumping or cracking. Further, since the inside of the chamber remains warm, there is no difference in film thickness between the first and second sheets.
[0014]
In the above lamp heat treatment apparatus, it is preferable that the cooling mechanism is a gas line that blows a cooling gas onto the support ring.
[0015]
In the above lamp heat treatment apparatus, it is preferable to use helium gas as the cooling gas.
[0016]
In the above lamp heat treatment apparatus, it is preferable that the cooling mechanism is a cooling ring for cooling the support ring.
[0017]
In the above lamp heat treatment apparatus, it is preferable that the cooling ring moves up and down to come into contact with the back surface of the support ring.
[0018]
In the above lamp heat treatment apparatus, the support ring is preferably made of silicon carbide.
[0019]
In the above lamp heat treatment apparatus, the cooling ring is preferably made of silicon carbide.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a lamp heat treatment apparatus according to the present embodiment.
[0021]
As shown in FIG. 1, the lamp heat treatment apparatus of the present invention has a metal chamber 101, in which a lamp unit 102 such as a tungsten halogen lamp or the like serving as a lamp light source and quartz for partitioning the lamp unit 102 are provided. A plate 103, a silicon carbide support ring 105 for horizontally supporting the wafer 104, a rotating cylinder 106 for mounting the silicon carbide support ring 105, a radiation thermometer 107 on the back side of the wafer 104, and a silicon carbide support ring A cooling gas line 110 for cooling only 105 in a short time or a cooling ring 111 made of silicon carbide is provided.
[0022]
Further, the chamber 101 is provided with a gas supply line 108 for supplying a process gas into the chamber 101 and a gas exhaust line 109 for discharging a processing gas. The rotation cylinder 106 is rotated by a driving mechanism, and can rotate the wafer 104 in the chamber 101 at 90 rotations / minute. The radiation thermometer 107 receives radiation light from the back surface of the wafer 104, converts the temperature to a temperature, and measures the temperature. In order to read the temperature in the plane of the wafer 104, a plurality of radiation thermometers are placed at positions from the center of the wafer 104 to the back surface on the outer periphery.
[0023]
The cooling gas line 110 faces the silicon carbide support ring 105, and is directly blown with the cooling gas. Helium gas is used as a cooling gas. In addition, the silicon carbide cooling ring 111 is located below the silicon carbide support ring 105, and can contact and separate from the back surface of the silicon carbide support ring 105 by performing up and down movement. .
[0024]
The case where the wafer 104 is oxidized using the lamp heat treatment apparatus of the present invention having such a cooling mechanism will be described below.
[0025]
First, the wafer 104 is loaded into the chamber 101 and placed on the support ring 105 made of silicon carbide. Next, a desired process gas, for example, oxygen gas is supplied from the gas supply line 108, and the heat treatment is performed while the lamp unit 102 is turned on and the wafer 104 is rotated.
[0026]
In order to eliminate the difference in the oxide film thickness between the first and second substrates in the continuous process, a preheat process of lighting the lamp unit 102 for 5 to 10 minutes without the wafer 104 is performed. Thereafter, helium gas is flowed through the cooling gas line 110 facing the silicon carbide support ring 105 for 10 seconds at a flow rate of 10 liters / minute, and helium gas is directly blown onto the silicon carbide support ring 105 to be cooled in a short time. Alternatively, the silicon carbide cooling ring 111 is raised and brought into contact with the back surface of the silicon carbide support ring 105 for 10 seconds, the silicon carbide support ring 105 is cooled in a short time, and then the silicon carbide cooling ring 111 is lowered.
[0027]
Next, the first wafer 104 is carried into the chamber 101, and the first wafer 104 is subjected to a heat treatment. After the heat treatment of the first wafer 104 is completed and carried out, the second wafer 104 is carried into the chamber 101 and heat treated. After the third wafer and subsequent wafers have been processed and unloaded, the next wafer 104 is loaded into the chamber 101 and heat-treated.
[0028]
As described above, before the first wafer is put into the silicon carbide support ring 105 after the pre-heat treatment for eliminating the difference in the oxide film thickness between the first and second sheets in the continuous processing, the helium is placed on the silicon carbide support ring 105. By directly blowing the gas, only the support ring 105 made of silicon carbide can be cooled in a short time.
[0029]
Alternatively, the silicon carbide cooling ring 111 is brought into contact with the back surface of the silicon carbide support ring 105, and the heat accumulated in the silicon carbide support ring 105 is directly released to the silicon carbide cooling ring 111, and the silicon carbide support ring Only 105 can be cooled in a short time.
[0030]
Thus, when the first wafer is loaded, the temperature difference between the center and the outer periphery of the wafer can be suppressed to 100 ° C. or less, and the wafer can be prevented from jumping or cracking. Further, since only the silicon carbide support ring 105 is cooled in a short time, the inside of the chamber is kept warm, so that there is no difference in film thickness between the first and second sheets.
[0031]
In the present embodiment, the wafer oxidation process has been described, but it goes without saying that the same effect can be obtained by applying the present invention to other nitriding processes or simple heat treatments.
[0032]
Also, the cooling mechanism of the silicon carbide support ring has been described with respect to the cooling gas line and the silicon carbide cooling ring, but it goes without saying that the effects of the present invention can be obtained if either one is provided.
[0033]
Further, although the support ring made of silicon carbide and the cooling ring made of silicon carbide are used, they may be made of other materials having substantially the same thermal conductivity as the wafer.
[0034]
【The invention's effect】
As described above, the lamp heat treatment apparatus of the present invention can cool only the support ring in a short time without cooling the inside of the chamber before the first wafer after the preheat treatment is loaded in the continuous processing. it can. Therefore, when the first wafer is loaded, the temperature difference between the center and the outer periphery of the wafer is suppressed to 100 ° C. or less, and it is possible to prevent the wafer from jumping or cracking. Further, since the inside of the chamber remains warm, there is no difference in film thickness between the first and second sheets.
[Brief description of the drawings]
FIG. 1 is a schematic view of a lamp heat treatment apparatus of the present invention. FIG. 2 is a schematic view of a conventional lamp heat treatment apparatus.
101 Chamber 102 Lamp unit 103 Quartz plate 104 Wafer 105 Silicon carbide support ring 106 Rotating cylinder 107 Radiation thermometer 108 Gas supply line 109 Gas exhaust line 110 Cooling gas line 111 Silicon carbide cooling ring

Claims (7)

A heating lamp unit provided at an upper part in the chamber;
A radiation thermometer provided at a lower portion in the chamber,
A support ring for mounting a wafer provided in the chamber;
A rotating cylinder for mounting and rotating the support ring,
A lamp heat treatment apparatus, comprising: a cooling mechanism for cooling the support ring. The lamp heat treatment apparatus according to claim 1, wherein the cooling mechanism is a gas line that blows a cooling gas to the support ring. The lamp heat treatment apparatus according to claim 2, wherein helium gas is used as the cooling gas. The lamp heat treatment apparatus according to claim 1, wherein the cooling mechanism is a cooling ring that cools the support ring. The lamp heat treatment apparatus according to claim 4, wherein the cooling ring moves up and down to contact a back surface of the support ring. The lamp heat treatment apparatus according to any one of claims 1 to 5, wherein the support ring is made of silicon carbide. The lamp heat treatment apparatus according to claim 4 or 5, wherein the cooling ring is made of silicon carbide.

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