JPH0568540B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for manufacturing a shroud used in an apparatus for manufacturing a film-like semiconductor containing Ga.

In this specification, the term "aluminum" includes not only pure aluminum but also aluminum alloys. However, the term "aluminum element" does not include aluminum alloys.

Conventional technology and its problems For example, MBE of semiconductor films containing Ga such as GaAs
When manufacturing with semiconductor manufacturing equipment such as equipment, film formation in an ultra-high vacuum is an essential condition in order to obtain higher performance. Therefore,
A shroud is used in the deposition chamber of the MBE equipment. A conventional shroud has a cylindrical shape made of a stainless steel plate, and a stainless steel tube is spirally wound around the outer peripheral surface of the shroud, and a cooling fluid such as liquid nitrogen flows through the tube. When forming the semiconductor film, first, the shroud is heated to 200 to 250°C to perform a baking treatment to remove moisture adsorbed on the surface of the shroud, and then a cooling fluid is poured into the stainless steel tube. The shroud is cooled by this cooling fluid, and residual gas is adsorbed on the surface of the shroud in the evacuated film forming chamber, thereby creating an ultra-high vacuum.
However, in conventional shrouds, the cylinder body and tube are made of stainless steel, so they are heavy and
Moreover, there was a problem that the thermal conductivity was not sufficient. If the thermal conductivity is insufficient, it will take time for the entire shroud to be evenly heated during the above-mentioned baking process, and it will also take time for the surface of the shroud to cool down to a predetermined temperature when cooling fluid is flowed. There was a problem.

Therefore, it has been considered to make a shroud using aluminum, which is lighter in weight than stainless steel, has excellent thermal conductivity, and has a small surface gas release coefficient. The reality is that shrouds made of aluminum have not yet been realized because if they adhere, they will corrode and create through holes.

An object of the present invention is to provide a method for manufacturing a shroud for semiconductor manufacturing equipment that solves the above problems.

Means for Solving the Problems According to the method of manufacturing a shroud for semiconductor manufacturing equipment according to the present invention, after producing an aluminum shroud cylinder having a cooling fluid circulation portion on the peripheral wall, at least the inner surface of the inner and outer surfaces of the aluminum shroud body is fabricated. The method is characterized in that the coating layer made of the above compound is formed by implanting ions that react with the aluminum element and create a compound that is not attacked by gallium, using an ion implantation method.

In the above, the shroud cylindrical body may be one in which an aluminum cooling fluid distribution pipe is spirally wound and bonded to the outer peripheral surface of an aluminum cylinder, or a cylinder for cooling fluid distribution such as a roll bond panel. There is one in which an aluminum plate-like body with a tubular bulge is formed into a cylindrical shape and the abutted parts are joined.

Further, in the above, there are many ions that react with the aluminum element to form compounds that are not attacked by gallium, and among them, for example, nitrogen ions, oxygen ions, carbon ions, etc. are used. These ions are easily gasified by _N2 ,
Obtained from O ₂ , C, etc. The compound created by the reaction between the above ions and aluminum element is
These include AlN, Al ₂ O ₃ and AlC. Further, the thickness of the compound coating layer is preferably within the range of 0.1 to 1 μm. The reason is that if the thickness of the coating layer is less than 0.1 μm, the corrosion resistance of the coating layer against gallium will not be sufficient, and the above thickness cannot be increased beyond 1 μm depending on ion implantation. It is from. The thickness of the covering layer is controlled by controlling the accelerating voltage related to the implantation depth, the ion implantation current related to the implantation layer, etc. during ion implantation. The thickness of the above coating layer is 0.1~1μ
For example, to set the acceleration voltage to 50 to 500KV
The ion implantation current was controlled at an implantation dose of 1×10 ¹⁸ ~
The number of particles is controlled to be 1×10 ¹⁹ pieces/cm ² .

Examples of the present invention will be shown below along with comparative examples.

Examples Example 1 First, a cylinder for a shroud having a cooling fluid circulation portion on its peripheral wall was made from an aluminum material. Next, using this shroud cylinder as a target, 1×10 ¹⁹ nitrogen ions/cm ² were implanted into its inner surface at an acceleration voltage of 300 KV. Then, an AlN layer with a thickness of 1 μm was formed on the inner surface of the cylinder. and,
After attaching 1 g of Ga to the inner surface of the cylindrical body for diuraud, a thermal cycle test of heating at 200°C for 24 hours and then cooling with liquid nitrogen for 30 minutes was repeated for 6 cycles to examine corrosion caused by Ga. As a result of observing the inner surface of the cylinder, no corrosion by Ga was observed.

Example 2 Carbon ions were used as the implanted ions during ion implantation, and the acceleration voltage was 100 KV and the ion implantation amount was 1.
×10 ¹⁸ pieces/cm ² An AlC layer with a thickness of 0.5 μm was formed on the inner surface of the shroud cylinder in the same manner as in Example 1 above, and corrosion by Ga was examined in the same manner as in Example 1 above. Ta. As a result, no corrosion by Ga was observed on the inner surface of the shroud cylinder.

Example 3 Oxygen ions were used as the implanted ions during ion implantation, the acceleration voltage was 300 KV, and the ion implantation amount was 1.
×10 ¹⁹ pieces/cm ² , but in the same manner as in Example 1 above, a 1 μm thick Al ₂ O ₃ layer was formed on the inner surface of the shroud cylinder, and in the same manner as in Example 1 above, it was eroded by Ga. I looked into it. As a result, no corrosion by Ga was observed on the inner surface of the shroud cylinder.

Comparative Example First, a cylindrical body for a shroud having a cooling fluid circulation portion on the peripheral wall was made from an aluminum material. After depositing 1 g of Ga on the inner surface of the shroud cylinder, a thermal cycle test of heating at 200°C for 24 hours and then cooling with liquid nitrogen for 30 minutes was repeated for 6 cycles to examine corrosion caused by Ga. As a result of observing the inner surface of the cylinder, severe corrosion by Ga was observed.

Effects of the Invention In the method for manufacturing a shroud for semiconductor manufacturing equipment according to the present invention, after an aluminum shroud cylinder having a cooling fluid circulation portion on the peripheral wall is fabricated, at least the inner surface of the inner and outer surfaces thereof is implanted by ion implantation. It is characterized by forming a coating layer made of the above compound by implanting ions that react with the aluminum element and create a compound that is not attacked by gallium, so compared to conventional stainless steel products. It is possible to easily manufacture a shroud that is lightweight, has good thermal conductivity, and has corrosion resistance against Ga that is equivalent to that of stainless steel. In particular, since it has excellent thermal conductivity, it is possible to shorten the baking treatment time during semiconductor film formation compared to conventional products, and it is also possible to reduce the time required for baking when forming a semiconductor film. Cooling efficiency is improved, and residual gas adsorption rate during semiconductor film formation is improved.

Furthermore, since the shroud cylinder is made from aluminum, it is easier to process than when it is made from stainless steel.

In addition, since the coating layer is formed by ion implantation, moisture is not adsorbed to this layer when it is formed, so when shrouds manufactured by this method are used in MBE equipment, etc. for,
It is sufficient to simply perform the conventional baking process during film formation of a semiconductor film.

In addition, since the coating layer is formed by ion implantation, this layer has excellent thermal cycling properties, including heating to about 250℃ for degassing purposes and liquid nitrogen during semiconductor film formation. Even after repeated cooling, the film does not peel or crack.

Furthermore, since aluminum has a lower gas release coefficient than stainless steel, there is less risk of lowering the degree of vacuum in the semiconductor film deposition chamber in the MBE apparatus.

Claims (1)

[Claims] 1. After making an aluminum shroud cylinder having a cooling fluid circulation part on its peripheral wall, a compound that reacts with the aluminum element and is not attacked by gallium is created on at least the inner surface of both the inner and outer surfaces thereof by ion implantation. 1. A method for manufacturing a shroud for semiconductor manufacturing equipment, comprising forming a covering layer made of the above compound by implanting ions.