JPH01105530A - Manufacturing method of semiconductor device - Google Patents

Abstract

PURPOSE:To improve a yield in a heat treatment process by forming a target pattern of a constant emissivity in a part of the surface of a semiconductor wafer, and by detecting electromagnetic waves from the pattern surface with a pyrometer and making an accurate temperature detection. CONSTITUTION:A semiconductor wafer 1, housed in a heat treatment device equipped with a temperature detection means composed of a pyrometer 13, is heat treated as specified by heating it with a lamp. On that occasion a target pattern 2 for detecting temperatures of constant emissivity is formed on a part of the surface of the wafer 1. Detection of electromagnetic waves emitted from the pattern 2 of constant emissivity makes it possible to make an accurate temperature measurement not affected by patterns of a circuit formed region or the quality of materials. This enables the yield in a heat treatment process to be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lamp heating technique used in the manufacturing process of semiconductor devices, and relates to a technique that is effective when applied to improve the accuracy of temperature detection of semiconductor wafers.

[Conventional technology]

Regarding lamp heating technology used in the manufacturing process of LSI etc., see Kogyo Kenkyukai Co., Ltd.,
"Electronic Materials/Special Volume" published on November 15, 1988, P87
~P91, and its outline is as follows.

In other words, the lamp heating technology described above is capable of short-time heat treatment, heat treatment at a wide range of temperatures from low to high temperatures, and rapid heating and cooling, making it possible to control the speed of heating and cooling. Because of its features such as the ability to perform single-wafer processing through automation, it is used as an alternative to heating methods using electric furnaces in annealing processes after ion implantation, glass reflow processes, etc.

Furthermore, in recent years, lamp heating technology has become indispensable in manufacturing processes for LSIs and the like, and has also come to be used in processes such as forming thin films on MOS gate electrodes and sintering processes.

A feature of the above-mentioned lamp heating technology is that semiconductor wafers (hereinafter referred to as wafers) can be heat-treated in a short time, and therefore, wafer temperature control is an important factor when performing this heat treatment.

Therefore, the above-mentioned heat treatment equipment is usually equipped with a temperature detection means consisting of a pyrometer and a temperature control section connected to this, and this pyrometer detects electromagnetic waves of a specific wavelength emitted from a wafer heated by a lamp. This is converted into an electrical signal, and the temperature control unit that receives this electrical signal controls the temperature of the wafer according to a predetermined temperature profile.

[Problem that the invention seeks to solve]

The present inventors have discovered that the following problems occur with the above-mentioned lamp heating technology.

In other words, the principle of the pyrometer is that a heated object radiates electromagnetic waves with a wavelength distribution according to its temperature to the outside at a predetermined emissivity (ea+m1sivity), but the emissivity is , the material of the object,
Since the emissivity differs depending on the film thickness, surface smoothness, etc., it is necessary to evaluate the emissivity by conducting a sampling test on the wafer in advance.

However, since the pattern and material of the circuit forming area of a wafer change at each step in the wafer process, the emissivity of the wafer changes accordingly, and if the steps are different, there will be errors in the accuracy of temperature detection by the pyrometer. It arises.

As a result, it becomes impossible to heat the wafer according to a predetermined temperature profile, and for example, variations in ion distribution occur in the annealing process after ion implantation, and M
This causes variations in film thickness in the process of forming a thin film on an OS gate electrode, etc., which causes a decrease in yield in various heat treatment processes using lamp heating.

Furthermore, evaluating the emissivity of each step of the wafer process in order to prevent errors in wafer temperature detection is unrealistic as it significantly reduces the throughput.

The purpose of the present invention has been made in view of the above-mentioned problems.The purpose of the present invention is to accurately detect the temperature of a wafer when performing a predetermined heat treatment on the wafer using lamp heating technology. Our goal is to provide the technology that makes it possible.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical inventions disclosed in this application is as follows.

That is, when a semiconductor wafer housed in a heat treatment apparatus equipped with temperature detection means consisting of a pyrometer is heated with a lamp and subjected to a predetermined heat treatment, a temperature detection target with a constant emissivity is attached to a part of the surface of the semiconductor wafer. It forms a pattern.

[Effect]

According to the above means, the pyrometer detects the electromagnetic waves emitted from the temperature detection target pattern with a constant emissivity, thereby making it possible to accurately measure temperature without being affected by the pattern or material of the circuit formation area.

〔Example〕

FIG. 1 is a plan view of a wafer showing a target pattern for temperature detection in a semiconductor device manufacturing method according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of a heat treatment apparatus used in this embodiment. .

As shown in FIG. 1, in the semiconductor device of this embodiment, in the wafer state, a temperature detection target pattern (hereinafter simply referred to as target pattern) 2 is formed at the center of the surface of the wafer l, and around the temperature detection target pattern 2 is formed. A large number of circuit formation regions 3 are formed.

The outer shape and area of the target pattern 2 are made equal to the outer shape and area of each circuit forming region 3, and a thin film of 5 iOa is coated on the surface with a uniform thickness, and 1.
The surface is adhered to form a smooth surface.

The thin film made of SiO Since the temperature needs to be constant, it is necessary to mask the surface of the wafer 1 except when using this target pattern 2 to detect the temperature of the wafer 1.

Next, the wafer 1 on which the target pattern 2 is formed is
The heat treatment process will be explained.

The heat treatment process of this example uses a CVD apparatus 4 shown in FIG. 2 as a heat treatment apparatus to form a thin film of metal or the like on the surface of a wafer 1 housed in a reaction chamber 5 that can be depressurized to a predetermined degree of vacuum. This is the process of

First, when the wafer 1 is carried into the reaction chamber 5 through the shutter 6 on the side wall of the reaction chamber 5, a pair of wafer cranes: jr, 7 driven by a drive mechanism (not shown) move the wafer l.
The wafer 1 is fixed to the lower end of the chuck 8 installed at the upper part of the reaction chamber 5. that time,
The circuit forming area 3 of the wafer 1 is located on the lower surface side.

Next, a pair of exhaust ports 9 arranged at the upper part of the reaction chamber 5.
When the interior of the reaction chamber 5 is maintained at a predetermined degree of vacuum by suctioning a large amount of air from the reaction chamber 9, the tungsten halogen lamp 10 installed above the reaction chamber 5 is turned on, and the emitted light is emitted from the chuck 8. Transparent quartz window 11 installed at the upper end of
When the radiant heat is transmitted through the wafer 1 and irradiated onto the back surface of the wafer 1, the entire wafer 1 is uniformly heated by the radiant heat.

A cooling pipe 12 is installed on the outer periphery of the side wall of the reaction chamber 5 to prevent heat accumulation in the reaction chamber 5 and to heat only the wafer 1.

The surface of the wafer 1 heated by the tungsten halogen lamp 10 emits electromagnetic waves having a wavelength distribution according to the temperature, and the pyrometer 13 installed at the center of the bottom of the reaction chamber 5 detects this electromagnetic wave. Convert that energy into an electrical signal.

At this time, since the pyrometer 13 is located directly below the target pattern 2 formed on the surface of the wafer 1, the electromagnetic waves detected by the pyrometer 13 are electromagnetic waves emitted from the surface of the target pattern 20.

Next, a control unit 14 connected to the pyrometer 13 receives the electrical signal and controls the temperature of the wafer 1 according to a temperature profile set in advance based on the emissivity of the target pattern 2.

When the wafer l reaches a predetermined temperature, a reaction gas G made of a metal fluoride such as W F s is introduced into the reaction chamber 5 from a pair of gas inlet ports 15 15 provided at the bottom of the reaction chamber 5 . is introduced, and when this reaction gas G is thermally decomposed on the heated surface of the wafer 1, a thin metal film such as W is deposited on the surface of the wafer 1.

As described above, according to this embodiment, the following effects can be obtained.

(1) Wafer 1 accommodated in reaction chamber 5 of CVD apparatus 4
When controlling the temperature of the wafer 1 according to a predetermined profile by heating the wafer 1 with a tungsten halogen lamp 10 and detecting electromagnetic waves emitted from the surface with a pyrometer 13, the material, film thickness, and surface If a target pattern 2 with a constant smoothness is formed and the electromagnetic waves radiated from the surface of the target pattern 2 are detected by the pyrometer 13, temperature detection is performed by the electromagnetic waves radiated from the target pattern 2 with a constant emissivity. Therefore, accurate temperature measurement is possible without being affected by the material or shape of the surface of the circuit forming area 30.

(2) According to (1) above, the wafer 1 can be heated according to a predetermined temperature profile, so that the yield of the CVD process using lamp heating is improved.

(3) According to (2) above, a highly reliable semiconductor device can be obtained.

Above, the invention made by the present inventor has been specifically explained based on Examples, but the present invention is not limited to the Examples (although it is understood that various changes can be made without departing from the gist of the invention). Needless to say.

For example, the material of the surface of the target pattern is SiO2
Although not limited to, it is necessary that the properties do not change due to lamp heating.
It is preferable to use an insulating film material such as z or 5i4Na.

Further, the target pattern can have any shape or area, and can be formed at any location on the surface of the sea urchin/%.

The above explanation has mainly been about the case where the invention made by the present invention is applied to the CVD process, which is its field of application, but the invention is not limited to this, and examples include, for example, annealing after ion implantation, sintering, glass It can be widely applied to wafer heat treatment processes that use lamp heating, such as anti-reflow and reflow processes.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

That is, when a semiconductor wafer housed in a heat treatment apparatus equipped with temperature detection means consisting of a pyrometer is heated with a lamp and subjected to a predetermined heat treatment, a target pattern with a constant emissivity is formed on a part of the surface of the semiconductor wafer. If a pyrometer is used to detect the electromagnetic waves emitted from the surface of the target pattern, it is possible to accurately detect the temperature unaffected by the pattern or material of the circuit formation area. The yield of the heat treatment process is improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a wafer showing a target pattern for temperature detection in a method for manufacturing a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of a heat treatment apparatus used in this embodiment. DESCRIPTION OF SYMBOLS 1...Semiconductor wafer, 2...Target pattern for temperature detection, 3...Circuit formation area, 4...CVD device,
5...Reaction chamber, 6...Shutter, 7...Wafer clamp, 8...Chuck, 9...Exhaust port, 10...
・Tungsten halogen lamp, 11...Quartz window, 1
2... Cooling pipe, 13... Pyrometer, 14...
Control unit, 15... Gas inlet, G... Reaction gas.

Claims (1)

[Claims] 1. When a semiconductor wafer housed in a heat treatment apparatus equipped with temperature detection means consisting of a pyrometer is heated with a lamp to perform a predetermined heat treatment, a part of the surface of the semiconductor wafer has an emissivity. A method for manufacturing a semiconductor device, comprising forming a target pattern for detecting a constant temperature. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the temperature detection target pattern is formed in the center of the surface of the semiconductor wafer. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the temperature detection target pattern is formed of an insulating material.