JP2002222768A - Jig for semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jig for a semiconductor, which can raise the quality of a heat-treated wafer. SOLUTION: A jig 1 for a semiconductor is one which is used for a heat treatment of a wafer in a semiconductor process, the jig 1 is constituted of a silicon carbide film formed by a CVD method, a wafer pocket 10, which is used as a recessed place for mounting the wafer, is provided in the top face 12 of the jig 1 and at least a light-shielding layer 13 is provided in the interior of the jig 1 so as to cover the wafer pocket 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is made of silicon carbide (hereinafter abbreviated as CVD-SiC) produced by a CVD method, and is mainly used for heat treatment of a wafer in a semiconductor device manufacturing process including an epitaxial growth process. The present invention relates to a jig for semiconductor such as a susceptor used.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, there are various heat treatment steps for subjecting a wafer to heat treatment such as an epitaxial growth step, a CVD step, and an annealing step.
The epitaxial growth step is a process of growing a semiconductor crystal on a wafer serving as a base material. In the case of manufacturing a device made of a silicon semiconductor, a silicon single crystal film is deposited and grown on the wafer. In the epitaxial growth step, the wafer is placed on a semiconductor jig such as a susceptor.
As a constituent material of the jig for semiconductor, a material in which the surface of a high-purity graphite material is coated with high-purity silicon carbide has been widely used. Also, similar semiconductor jigs have been used in various heat treatment steps such as the CVD step and the annealing step.

However, in a jig for a semiconductor formed by coating the surface of a graphite material with silicon carbide, the physical properties (coefficient of thermal expansion) of the silicon carbide and the graphite material are different. In some cases, the silicon film was peeled off or cracked, making it unusable. The thickness of the silicon carbide film is 5
When the heat treatment process is performed in an atmosphere as thin as about 0 to 200 μm and highly corrosive, there is a problem that pinholes are generated in the silicon carbide film and impurities in the graphite material are released therefrom.

In recent years, it has been considered to reduce the heat capacity of a semiconductor jig in order to improve the processing cycle of a wafer for cost reduction. Regarding this, it has been studied to reduce the thickness of the semiconductor jig. However, when a graphite material is used as a base material, it is difficult to make the thickness smaller than a predetermined value in view of strength.

For this reason, a semiconductor jig made of CVD-SiC has been proposed. CVD-SiC is CV
A jig for semiconductors manufactured using the D process, which has a very dense carbon structure and high hardness. for that reason,
The strength is strong, and the thickness and the heat capacity can be reduced as compared with a semiconductor jig using a mere graphite material.

[0006]

However, CVD-Si
The semiconductor jig made of C has the following problems. C
In a jig for semiconductor made of VD-SiC, CVD-Si
Due to the nature of C, light from a xenon lamp used as a heat source during heat treatment may pass through a semiconductor jig and reach a wafer.

Further, since the wafer pocket of the semiconductor jig is formed by machining, there are many irregularities formed of cutter marks on the mounting surface in the wafer pocket. Therefore, the unevenness may cause variations in the amount of light transmitted by the xenon lamp, resulting in a significant reduction in wafer processing quality and a reduction in processing yield. Of course, if the thickness of the semiconductor jig is increased, the above problem can be avoided. However, this method is not preferable because the heat capacity of the semiconductor jig becomes large and heat hardly reaches the wafer.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a jig for a semiconductor capable of improving the processing quality and processing efficiency of a wafer.

[0009]

According to a first aspect of the present invention, there is provided a semiconductor jig used for heat treatment of a wafer in a semiconductor process, wherein the semiconductor jig is made of silicon carbide generated by a CVD method. On the top surface of the jig, there is provided a wafer pocket serving as a recess for mounting a wafer, and inside the jig,
A semiconductor jig is provided with a light shielding layer so as to cover at least the wafer pocket.

In the present invention, the light-shielding layer has an area at least as large as or larger than the wafer mounting surface in the wafer pocket. What is the wafer mounting surface?
When a wafer is placed in the wafer pocket,
This is the surface where the wafer abuts in the wafer pocket (see FIG. 1). The phrase “the light-shielding layer is provided so as to cover the wafer pocket” means that when the light-shielding layer is projected onto the wafer pocket, the wafer pocket is hidden by the projection surface of the light-shielding layer.

Next, the operation and effect of the present invention will be described.
Consider a case where a wafer is mounted on a jig for a semiconductor and a lamp is heated from the top side and the opposite bottom side of the jig for a semiconductor as shown in FIG. The light in the lamp heating from the bottom side is blocked by the light shielding layer, and only heat can be conducted to the wafer pocket. Therefore, it is possible to prevent the thermal variation due to the unevenness existing in the wafer pocket due to the light from being transferred to the wafer, thereby improving the processing quality of the wafer and increasing the processing yield. Furthermore, according to the present invention, a jig for a semiconductor that can use lamp heating that can be rapidly heated can be obtained, so that the processing efficiency for a wafer can be improved. In addition, CVD-SiC has high strength and thus has excellent durability and high thermal conductivity, so that the wafer can be quickly heated.

As described above, according to the present invention, it is possible to provide a semiconductor jig capable of improving the processing quality and processing efficiency of a wafer.

The semiconductor jig according to the present invention can be used in a wafer heat treatment step such as a CVD step or an annealing step, in addition to the epitaxial growth (see the embodiment) described later.

Next, as in the second aspect of the present invention, the light shielding layer has a wavelength of 400 to 800 nm.
% Or more. A heat source that enables rapid heating is very effective for shortening the processing time, and a xenon lamp is one such heat source. Since the light-shielding layer according to the present invention is opaque to the wavelength in the above-mentioned range by 50% or more, when a xenon lamp is used as a heat source,
The light emitted from the xenon lamp via the semiconductor jig can be prevented from transmitting to the wafer pocket.

Note that a xenon lamp is a type of discharge lamp that utilizes discharge light emission in xenon, and its spectral distribution has many continuous spectrum parts and emits light showing a spectrum similar to natural daylight. Further, it is a bright light source close to a point light source and has a characteristic of emitting light stably at the same time as lighting. For this reason, the heating on / off control is easy, which is very effective for shortening the processing time.

For light having a wavelength of 400 to 800 nm, 5
If the transmittance is less than 0%, the processing quality of the wafer may be degraded. Of course, it is most preferable that the light of the xenon lamp is not transmitted at all by the 100% opacity, that is, by the light shielding layer. Even if the light from the lamp does not transmit at all, the semiconductor jig is heated by the lamp and heat is conducted to the wafer through the semiconductor jig, so that the heat treatment can be performed without any problem.

Further, as described above, since the xenon lamp emits light close to natural daylight, if the wavelength in the visible light region can be cut off, a sufficient effect can be obtained as the light shielding layer according to the present invention.

Next, it is preferable that the light shielding layer is made of metallic silicon. Thus, when manufacturing a jig for semiconductor by the CVD method, the metal silicon plate can be used as a core material as it is.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment A semiconductor jig according to an embodiment of the present invention is shown in FIG.
This will be described with reference to FIG. As shown in FIG.
This is a semiconductor jig 1 used for heat treatment of the wafer 2 in a semiconductor process. The jig 1 for semiconductor of this example is CV
As shown in FIGS. 1 and 2, a wafer pocket 10 serving as a recess for mounting the wafer 2 is formed on the top surface 12 of the jig 1 for a semiconductor.
And at least a wafer pocket 1
The light shielding layer 13 is provided so as to cover 0.

The semiconductor jig 1 of this embodiment will be described in detail. As shown in FIG. 1, the semiconductor jig 1 of the present embodiment is a disk. The top surface 12 is provided with a circular wafer pocket 10. The mounting surface 101 of the wafer pocket 10 is a surface that comes into contact with the wafer 1 when the wafer 2 is mounted on the wafer pocket 10. Since the mounting surface 101 is formed by cutting the wafer pocket 10 as described later, the mounting surface 101 has irregularities of about 1 to 10 μm on average.

A light-shielding layer 13 is provided between the bottom surface 11 opposite to the top surface 12 and the wafer pocket 10. The light shielding layer 13 is made of metal silicon as described later. The mounting surface 101 and the light-shielding layer 13 have the same shape, and the projection surface obtained by projecting the light-shielding layer 13 onto the wafer pocket 10 and the mounting surface 101 are configured to have substantially the same position and shape.

Next, a method of manufacturing the semiconductor jig 1 will be described. First, a metal silicon plate serving as the light shielding layer 13 is prepared by machining a silicon single crystal into a predetermined size. Next, an SiC layer is formed around the metal silicon plate by using the CVD method. At this time, in the CVD method, methyltrichloroethane, methylchlorosilane, or the like is used as a source gas, hydrogen is introduced as a carrier gas, and the temperature is set to 1200 ° C. and the degree of vacuum is 26664.4 Pa (200 ° C.).
Torr).

As a result, the CVD was performed around the metal silicon plate.
A SiC layer was formed, and a CVD-SiC plate having a metal silicon plate as a core was obtained as a whole. Finally, CVD-S
Machine the top surface of the iC plate using a diamond whetstone,
A wafer jig 1 was obtained by providing a wafer pocket 10 for the wafer 2. Note that cutter marks (traces of blades used for processing) were present on the entire surface of the wafer pocket 10 formed by machining.

Next, a heating method when using the semiconductor jig 1 of this embodiment will be described. As shown in FIG. 3, in order to heat the wafer 2, the side of the top surface 12 of the jig 1
On the side of the bottom surface 11, a xenon lamp 31 as a heat source is arranged along the circumferential direction of the jig 1 for semiconductor.

Then, the jig 1 for semiconductor shown in this embodiment is heated by the above-mentioned heating method, and is actually 8 inches (20.3 inches).
When an epitaxial growth process was performed on the silicon wafer 2 having a diameter of 2 cm), the thickness variation of the single-crystal silicon film formed on the surface of the silicon wafer became 1% or less. For comparison, when a similar epitaxial growth process was performed using an ordinary semiconductor jig (not shown) without the light-shielding layer 13, the thickness variation of the single-crystal silicon film formed on the surface of the wafer 2 was reduced. 8%.

Next, the operation and effect of this embodiment will be described. The jig 1 for a semiconductor of this example has a light shielding layer 13 made of a metal silicon plate inside. And the metal silicon plate is hard to transmit light. When the wafer 2 is heated using the jig 1 for semiconductor by the heating method shown in FIG. Through the light-shielding layer 13 made of
Light does not reach the wafer pocket 10.

For this reason, it is possible to make it difficult for the unevenness of the wafer pocket 10, particularly the mounting surface 101, to be transferred to the wafer 2 when the lamp is heated. Therefore, the processing quality of the wafer 2 can be improved. Furthermore, since the jig 1 for semiconductor which can use the lamp heating which can be rapidly heated can be obtained, the processing efficiency for the wafer 2 can be improved.

As described above, according to the present embodiment, it is possible to provide a semiconductor jig capable of improving the processing quality and processing efficiency of a wafer.

[0029]

As described above, according to the present invention, it is possible to provide a semiconductor jig capable of improving the processing quality and processing efficiency of a wafer.

[Brief description of the drawings]

FIG. 1 is a sectional explanatory view of a jig for a semiconductor according to an embodiment.

FIG. 2 is a perspective view of a jig for a semiconductor according to the embodiment.

FIG. 3 is an explanatory diagram of a heating method in the embodiment.

[Explanation of symbols]

 1. . . 10. jig for semiconductor, . . 11. wafer pocket, . . Top surface, 13. . . 1. light-shielding layer; . . Wafer,

Continued on the front page F term (reference) 4G077 AA03 BA04 DA01 DB01 EG03 EG04 FK02 SA12 TA12 5F045 AB06 AC07 AD16 AE25 AF03 BB02 BB08 BB13 EK14 EK18 EM02 EM09 GH08

Claims (3)

[Claims] 1. A semiconductor jig used for heat treatment of a wafer in a semiconductor process, wherein the semiconductor jig is made of silicon carbide generated by a CVD method. The surface is provided with a wafer pocket serving as a recess for mounting a wafer, and a light shielding layer is provided inside the jig for semiconductor so as to cover at least the wafer pocket. Jig for semiconductors. 2. The jig according to claim 1, wherein the light shielding layer is opaque to light having a wavelength of 400 to 800 nm by 50% or more. 3. The jig according to claim 1, wherein the light shielding layer is made of metal silicon.