TY - JOUR
T1 - High-rate deposition of amorphous silicon films by microwave-excited high-density plasma
AU - Inoue, Hirotada
AU - Tanaka, Kouji
AU - Sano, Yuichi
AU - Nishimura, Takehiro
AU - Teramoto, Akinobu
AU - Hirayama, Masaki
AU - Ohmi, Tadahiro
PY - 2011/3/1
Y1 - 2011/3/1
N2 - In this study, the deposition of amorphous silicon (a-Si) thin films using a microwave-excited high-density plasma system is described. We investigate the effects of plasma excitation gas species (argon or helium), total gas pressure, silane (SiH4) flow rate, and substrate stage temperature, estimating the resultant films from cross-sectional morphology, photoconductivity, and dark conductivity measured without lightinduced degradation. It is confirmed that high-quality a-Si films (photosensitivity = 1.29 × 106) can be formed in the plasma excitation gas helium at a pressure of 13.3 Pa by relatively high rate (1.1 nm/s) deposition. At the same time, we measure the plasma emission derived from various radicals such as Si and SiH radicals in order to discuss the mechanism of radical generation in the plasma. The result of the measurement implies that when argon is used as plasma excitation gas, metastable states of argon markedly dissociate silane, which produces low-quality a-Si films. On the other hand, it seems that electrons dissociate silane mainly, which produces high-quality a-Si films, in helium.
AB - In this study, the deposition of amorphous silicon (a-Si) thin films using a microwave-excited high-density plasma system is described. We investigate the effects of plasma excitation gas species (argon or helium), total gas pressure, silane (SiH4) flow rate, and substrate stage temperature, estimating the resultant films from cross-sectional morphology, photoconductivity, and dark conductivity measured without lightinduced degradation. It is confirmed that high-quality a-Si films (photosensitivity = 1.29 × 106) can be formed in the plasma excitation gas helium at a pressure of 13.3 Pa by relatively high rate (1.1 nm/s) deposition. At the same time, we measure the plasma emission derived from various radicals such as Si and SiH radicals in order to discuss the mechanism of radical generation in the plasma. The result of the measurement implies that when argon is used as plasma excitation gas, metastable states of argon markedly dissociate silane, which produces low-quality a-Si films. On the other hand, it seems that electrons dissociate silane mainly, which produces high-quality a-Si films, in helium.
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U2 - 10.1143/JJAP.50.036502
DO - 10.1143/JJAP.50.036502
M3 - Article
AN - SCOPUS:79953102448
VL - 50
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 3
M1 - 036502
ER -