EPITAXIAL GROWTH OF SILICON BY ELECTRON BEAM EVAPORATION DEPOSITION

摘要

In this paper we report epitaxial growth of thin p-doped Si films at Si (100) substrates at deposition temperatures T_s = 600-1000°C under non-ultra-high vacuum conditions using high rate electron beam evaporation. It is established that fully crystalline Si based layers (～50 μm thick) can be fabricated at a deposition rate of ～l.5 μm/min. The crystallinity and stress were analyzed by Raman spectroscopy, which revealed a peak at 520 cm~(-1), confirming crystalline and stress-free silicon. Electron Backscatter Diffraction (EBSD) shows that the film growth proceeds epitaxially on the crystalline Si supporting substrate with excellent crystallinity at 800 and 1000°C. Hall effect measurements show that the film deposited at 1000°C has a resistivity of 5.01 Ωcm, carrier concentration of 4.93~(15) cm~(-3) and mobility of 253 cm~2V~(-1) s~(-1). These values comparable to those obtained for c-Si material grown using the same Si feedstock (solar grade Si). Secco etching tests were also performed to analyze the defect density in the films. The films deposited at higher temperatures have lower etch pits density. These results demonstrates that high temperature electron beam deposition can be considered as a promising and cost-effective alternative to conventional CVD based growth of epi-Si layers.