Large area multi-zone type VHF-PCVD system for a-Si and /spl mu/c-Si deposition

Large area plasma enhanced chemical vapor deposition (PCVD) system consisted of arrays of novel U-shaped loop antenna type electrodes (array antenna) was developed to achieve high throughput deposition of amorphous silicon (a-Si) and microcrystalline silicon (/spl mu/c-Si) thin films at very high frequency (VHF). By the use of array antennas, simultaneous deposition on six substrates of over 1 m squares in size was realized at an excitation frequency of 85 MHz. The Si-H/sub 2/ stretching mode fraction, observed from the infrared absorption spectrum of a-Si film deposited at 200/spl deg/C and 12 nm/min, was negligible, and the non-uniformity of the deposition rate was /spl plusmn/12% for over 1000 mm/spl times/1200 mm. Standard dark conductivities were observed by both n-type and p-type doped a-Si films. The crystallinity of microcrystalline silicon films obtained from Raman spectra (Ic/Ia) was 10 at the deposition rate of 6 nm/min and was 5.1 at 30 nm/min.