JP2821212B2 - Refractory material and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a refractory material and a method for producing the same, and more particularly to a refractory material suitable for parts such as susceptors, furnace core tubes, and jigs used in semiconductor production. It is.

[Prior art and problems] Conventionally, as a part for manufacturing a semiconductor such as a susceptor, a part formed of quartz or carbon has been used. However, when a semiconductor is manufactured using these components, there is a disadvantage that impurities existing inside the components or impurities due to residual cleaning during cleaning are diffused outside due to a rise in temperature and contaminate the semiconductor.

Therefore, for the purpose of preventing contamination of the semiconductor due to diffusion of impurities from the quartz or carbon base material and protecting the base material itself, a thin film of a silicon carbide layer and / or a silicon nitride layer is formed on the surface of the base material by CV.
Refractory materials coated by the D method etc. are used. However, this refractory material has a thin film
m or more, peeling occurs in the thin film due to the difference in thermal expansion between the substrate and the thin film due to thermal effects during use,
The thin film may not be able to contribute to prevention of contamination of the semiconductor or protection of the substrate itself.

Further, the susceptor formed of carbon is liable to slip because heat is taken away by the bottom portion. For this reason, attempts have been made to use quartz glass having a low thermal conductivity for the bottom plate. However, Si particles may be generated in the quartz glass bottom plate, and may not be able to effectively contribute to prevention of contamination of the semiconductor and protection of the base material itself. Incidentally, a coating of a silicon carbide layer and / or a silicon nitride layer on a quartz glass bottom plate has been attempted in order to prevent utterance of Si particles. But in this case,
The silicon carbide layer and / or silicon nitride layer is peeled off due to the difference in thermal expansion coefficient between the quartz substrate and the silicon carbide layer and / or silicon nitride layer, which is not effective in preventing generation of Si particles. It cannot effectively contribute to the protection of the material itself.

The present invention has been made in view of such circumstances,
By forming a silicon carbide layer and / or a silicon nitride layer on a quartz substrate having a surface roughness Ra of 0.5 to 20 μm, the strength against thermal stress can be remarkably improved, and thus the occurrence of peeling due to thermal influence during use, An object of the present invention is to provide a refractory material that can prevent erosion due to chlorine vapor or the like during cleaning, and can further prevent generation of slip and generation of Si particles, and a method of manufacturing the same.

[Means and Actions for Solving the Problems] The first invention of the present application provides a quartz substrate having a surface roughness Ra of 0.5 to 20 μm, a silicon carbide layer formed on the quartz substrate, and / or
Alternatively, it is a refractory material including a silicon nitride layer.

The second invention of the present application provides a surface roughness Ra of 0.5
A method for producing a refractory material, comprising forming a silicon carbide layer and / or a silicon nitride layer on a quartz substrate having a thickness of about 20 μm.

Supplementary explanation of the present invention is that the thickness of the silicon carbide layer and / or the silicon nitride layer according to the present invention may be usually 10 μm or more. However, according to the method of the present invention, it is possible to increase the thickness of the silicon carbide layer and / or the silicon nitride layer to 100 μm or more while significantly improving the strength against thermal stress.

In the present invention, the surface roughness Ra of the quartz substrate is defined as described above because there is no effect of preventing the occurrence of peeling when Ra is less than 0.5 μm, and conversely, when Ra exceeds 20 μm, carbonization formed thereon is This is because it becomes difficult to coat the quartz substrate with the silicon layer and / or the silicon nitride layer, and it cannot effectively contribute to protection of the substrate itself.

Means for surface treatment of the quartz substrate include, for example, frost treatment, sand blast treatment, surface grinding and the like. In addition, by the etching using an acid, it is possible to remove a portion that has become weak due to the residual processing stress due to the surface treatment. As a result, it is possible to prevent a part which has become weak due to residual processing stress due to thermal stress after the silicon carbide layer and / or the silicon nitride layer is formed on the quartz base material from falling off. Etching with an acid is performed, for example, by immersing in a solution in which the volume ratio of 49 wt% HF: H ₂ O is adjusted to 1: 1 for 10 minutes.

According to the present invention, the surface roughness of the quartz substrate is 0.5 to 20 μm.
By forming a silicon carbide layer and / or a silicon nitride layer thereon, the strength against thermal stress can be remarkably improved, so that peeling occurs due to thermal influence during use and erosion due to chlorine vapor during cleaning. Generation can be prevented, and further, generation of slip and generation of Si particles can be prevented.

 Hereinafter, examples of the present invention will be described together with comparative examples.

Example 1 First, a quartz substrate having a thermal expansion coefficient of 5.7 × 10 ⁻⁷ was subjected to frost treatment with # 180 to have a surface roughness Ra of 1.2 μm. Next, after inserting this quartz substrate into a furnace, the substrate was heated to 1200 ° C., and H ₂ was used as a carrier gas at 0.5 L / min, SiCl ₄ was used as a silicon source gas at 1.0 L / min, 0.2 l of C ₃ H ₈ as carbon source gas
At a flow rate of 20 min / min to coat a silicon carbide layer having a thickness of 20 μm to form a susceptor.

That is, the susceptor according to the first embodiment has a configuration in which a silicon carbide layer having a thickness of 20 μm is coated on a quartz base material having a Ra of 1.2 μm.

Example 2 First, a quartz substrate having a thermal expansion coefficient of 5.7 × 10 ⁻⁷ was subjected to frost treatment with # 180 to have a surface roughness Ra of 1.2 μm. Next, after inserting this quartz substrate into a furnace, the substrate was heated to 1200 ° C., and H ₂ was used as a carrier gas at 0.5 L / min, SiCl ₄ was used as a silicon source gas at 1.0 L / min, 0.1% NH ₃ as nitrogen source gas
At a flow rate of 20 minutes per minute to coat a silicon nitride layer having a thickness of 20 μm to form a susceptor.

That is, the susceptor according to the second embodiment has a configuration in which a 20 μm-thick silicon nitride layer is coated on a quartz substrate having an Ra of 1.2 μm.

Example 3 First, a quartz substrate having a thermal expansion coefficient of 5.7 × 10 ⁻⁷ was subjected to frost treatment with # 180, and then the substrate was added to a solution in which the volume ratio of HF: H ₂ O was adjusted to 1: 1. Then, the surface roughness Ra was adjusted to 1.0 μm. Next, after inserting the quartz substrate into a furnace, the substrate was heated to 1200 ° C., and H ₂ was used as a carrier gas in a furnace.
A 20 μm-thick silicon carbide layer was coated by flowing SiCl ₄ as a silicon source gas at 1.0 l / min and C ₃ H ₈ as a carbon source gas at 0.2 l / min for 20 minutes to form a susceptor.

That is, the susceptor according to the third embodiment has a configuration in which a silicon carbide layer having a thickness of 20 μm is coated on a quartz substrate having an Ra of 1.0.

Comparative Example 1 First, the coefficient of thermal expansion was 5.7 × 10 ⁻⁷ , and the surface roughness Ra was 0.3 μm.
After inserting the quartz base material into the furnace, the base material was heated to 1200 ° C., and H ₂ was used as a carrier gas at 0.5 l / min, SiCl ₄ at 1.0 l / min as a silicon source gas, and a carbon source gas. the C ₃ H ₈ as 0.
A 20 μm thick silicon carbide layer was coated at a flow rate of 2 l / min for 20 minutes to form a susceptor.

That is, the susceptor according to Comparative Example 1 has a configuration in which a silicon carbide layer having a thickness of 20 μm is coated on a quartz base material having a Ra of 0.3 μm.

Comparative Example 2 First, a quartz substrate having a thermal expansion coefficient of 5.7 × 10 ⁻⁷ was subjected to frost treatment with # 5, and the surface roughness Ra of the substrate was set to 25 μm. Thereafter, while the substrate was heated to 1200 ° C., H ₂ was used as a carrier gas at 0.5 L / min, and SiCl ₄ was used as a silicon source gas at 1.0 L / min.
And NH ₃ as a nitrogen source gas at 0.1 / min for 20 minutes
A 20 μm silicon nitride layer was coated to form a susceptor.

That is, the susceptor according to Comparative Example 2 has a configuration in which a silicon nitride layer having a thickness of 20 μm is coated on a quartz base material having a Ra of 25 μm.

When the susceptors obtained in Examples 1, 2, and 3 and Comparative Examples 1 and 2 were used in an epitaxial manufacturing apparatus to produce an epitaxial wafer, the susceptor obtained in Comparative Example 1 was 7
Peeling occurred after repeated use, rendering it unusable. Comparative Example 2
The susceptor obtained in (1) was difficult to coat the silicon nitride layer and could not effectively contribute to the protection of the base material itself, and became unusable after a single use. On the other hand, according to the soapers obtained in Examples 1 to 3, no peeling was observed even when used 250 times under the same conditions, and a good epitaxial wafer could be manufactured for a long period of time.

〔The invention's effect〕

As described in detail above, according to the present invention, the surface roughness Ra is set to 0.
By forming a silicon carbide layer and / or a silicon nitride layer on a quartz substrate having a thickness of 5 to 20 μm, the strength against thermal stress can be remarkably improved, thereby causing peeling due to thermal influence during use and chlorine vapor during cleaning. Can prevent the occurrence of erosion due to
Further, it is possible to provide a refractory material capable of preventing generation of slip and generation of Si particles, and a method of manufacturing the same.

──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Yukio Ito 378 Oguni-machi, Oguni-machi, Oguni-machi, Nishiokitama-gun, Yamagata Prefecture Inside the Oguni Plant of Toshiba Ceramics Co., Ltd. No. 378 Toshiba Ceramics Co., Ltd. Oguni Works (72) Inventor Masayuki Kakuya Yamagata Pref. Oguni-machi, Oguni-machi, Nishiokitama-gun Oji-cho 378 Toshiba Ceramics Co., Ltd. Oguni Works (56) References JP-A-62-96349 A) JP-A-64-45792 (JP, A) JP-A-56-130347 (JP, A) JP-A-2-289476 (JP, A) Japanese Utility Model Application Sho-63-43423 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) C03C 15/00-23/00 C04B 41/87

Claims (2)

(57) [Claims] 1. A quartz substrate having a surface roughness Ra of 0.5 to 20 μm,
A refractory material comprising: a silicon carbide layer and / or a silicon nitride layer formed on the quartz substrate. 2. A surface roughness Ra of 0.5 to 20 μm by surface treatment.
A method for producing a refractory material, comprising forming a silicon carbide layer and / or a silicon nitride layer on a quartz substrate as described above.