RU2534388C2 - Method of cleaning carbide-silicon pipe - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of production of power silicon transistors, in particular to methods of processing a carbide-silicon pipe, applied for high-temperature processes in diffusion furnaces. In the method of the carbide-silicon pipe processing cleaning of the carbide-silicon pipe is carried out in a solution, consisting of ammonium bifluoride - NH₄HF₂, hydrochloric acid - HCl and de-ionised water- H₂O in a ratio of 1:1.5:4, respectively. The duration of processing constitutes 10±7 minutes. After the processing is finished, the pipe is washed in de-ionised water at room temperature for 30 minutes.

EFFECT: invention provides the reduction of duration and the process simplification, complete removal of soiling.

Description

The manufacture relates to the manufacturing technology of power silicon transistors, in particular to methods for processing silicon carbide tubes used for high temperature processes in diffusion furnaces. Known methods of processing products in various etchants at high temperatures [1].

The main disadvantage of these methods is the incomplete removal of impurities and various contaminants from the silicon carbide pipe. A known method of processing a silicon carbide pipe with a solution, which includes hydrofluoric acid — HF, hydrochloric acid — HC1 and deionized water — H ₂ O in a ratio of 1: 1: 3.5. The essence of this method is that the silicon carbide tube is subjected to a solution treatment for 20 ± 5 minutes [2].

The main disadvantage of this method is the length of the process, incomplete removal of contaminants, the use of unsafe hydrofluoric acid.

The aim of the invention is to reduce the duration and simplification of the process, the complete removal of contaminants.

This goal is achieved in that the removal of contaminants from the silicon carbide pipe occurs through the use of a solution that includes ammonium bifluoride - NH ₄ HF ₂ , hydrochloric acid - HC1 and deionized water - H ₂ O in a ratio of 1: 1.5: four. The processing time is 10 ± 7 minutes. At the end of the treatment, the pipe is washed in deionized water at room temperature and a time of 30 minutes. The essence of the method lies in the fact that the silicon carbide tube is subjected to a solution treatment for 10 ± 7 minutes. The quality of processing is determined using indicator paper, which should be applied to the wet inner surface of the pipe. If the indicator paper turns red, repeat the treatment. Then install the pipe in a cabinet and stand at room temperature for at least 11 hours. The invention is confirmed by the following examples.

EXAMPLE 1. The process is carried out on the installation of processing a silicon carbide pipe in a solution consisting of ammonium bifluoride, hydrochloric acid and deionized water with a ratio of components:

NH ₄ HF ₂ : HCl: H ₂ O

1: 1.5: 5.0

The temperature of the solution is room. The processing time is 15 ± 5 minutes. At the end of the treatment, the silicon carbide tube is washed in deionized water for 30 minutes. The quality of processing is determined using indicator paper.

EXAMPLE 2. The processing method is carried out analogously to example 1. The process is carried out on the installation of processing a silicon carbide pipe in a solution consisting of ammonium bifluoride, hydrochloric acid and deionized water with a ratio of components:

NH ₄ HF ₂ : HC1: H ₂ O

1: 1.5: 4.0

The temperature of the solution is room. The processing time is 10 ± 7 minutes. At the end of the treatment, the silicon carbide tube is washed in deionized water for 30 minutes. The quality of processing is determined using indicator paper. Thus, the proposed method in comparison with prototypes provides complete removal of contaminants, a safe processing process, reducing the duration of the process.

Literature

1. A.I. Kursonov. Materials for semiconductor devices and integrated circuits. M.: Higher School, 1980, pp. 88-89.

2. Patent No. 2377690, H 01 L 21/306, 12/27/2009

Claims (1)

A method of processing a silicon carbide pipe, including cleaning a silicon carbide pipe before carrying out high-temperature processes in a solution consisting of ammonium bifluoride (NH ₄ HF ₂ ), hydrochloric acid (HCl) and deionized water (H ₂ O), characterized in that As a solution, a solution is used, which includes ammonium bifluoride, hydrochloric acid and deionized water in the ratio of components 1: 1.5: 4 at room temperature, the duration of the process is 10 ± 7 minutes, then rinsing in deionized water is carried out for 30 minutes, the quality of processing is determined using indicator paper.