Process Development of Plasma-Enhanced Deposition of Epitaxial-Like Silicon Film and Its Application to Trace Metal Detection of Process Gas-Trichlorosilane

Trichlorosilane-TCS is an important raw material of semiconductor, LCD panels and photovoltaic industries, esspecially it is most important as the main material for polysilicon and electronic grade special gas - silane in the semiconductor industry, but more than 80% of raw materials to be dependent on foreign imports. The presence of trace metal impurities in electronic specialty gases (ESGs) can modify the electrical properties of the insulating or conducting layers in a semiconductor device. The importance of controlling these impurities in the etching and deposition processes has increased as the feature sizes have decreased and become more complex. The program objective with Shihlien Fine Chemical Cooperation (SFC Co.) is the technique development of standardized quantitative and qualitative trace metal analysis for TCS. However, due to it is flammable, toxic and corrosive, we can not directly measured trace metals from gas source. Various thickness (0.5-2 μm) intrinsic epitaxial-like silicon films will be deposited through optimized process parameters by plasma enhanced chemical vapor deposition system using the SFC manufacturing trichlorosilane as source gas, and these films are using as the samples of the trace metal measurements for the establishment of the qualitative and quantitative ppb~ppt detection technology of trace metal impurities.We can control the qualities of intrinsic epitaxial-like silicon films respectively after the measurements by ellipsometry, Fourier transform infrared spectroscopy, and four point probe method, which were verified the thickness, the crystallization, chemical bonding and the resistivity, as the following detection data bases of trace metal analysis. Then, the related chemical solution and samples were qualitatively and quantitatively detected by inductively coupled plasma mass spectrometry to establish the standard sample pretreatments and optimization processes of trace metal impurities after verifing the contamination source. And all the results of the sample containing trace metal impurities will be feedback to SFC Co. as purifing trichlorosilane to reduce trace metal impurities, to reach the level of electronic specialty gas demand of industry specifications. Hoping so as to improve fabrication ability of high-quality special gas from the domestic manufacturers and the key raw materials more suppliers for the domestic semiconductor industry.