p Channel thin ® lm transistor and complementary metal ± oxide ± silicon inverter made of microcrystalline silicon directly deposited at 320 ° C

We report a p channel thin ®lm transistor (TFT) made of directly deposited microcrystalline silicon (lc-Si). The lc-Si channel material is grown by plasma-enhanced chemical vapor deposition (PECVD) using dc excitation of a mixture of SiH4, SiF4 and H2, in a process similar to the deposition of hydrogenated amorphous silicon (a-Si:H). The deposition temperature for the lc-Si is 320°C and the highest post-deposition TFT process temperature is 280°C. By integrating this p TFT on a single lc-Si ®lm with an n channel TFT, we fabricated a complementary metal±oxide±silicon (CMOS) inverter of deposited lc-Si. The p channel lc-Si TFT represents a breakthrough in low-temperature Si TFT technology because p channel TFTs of a-Si:H have not been available to date. The integrated CMOS inverter is the building block of a new digital circuit technology based on directly deposited lc-Si. Ó 2000 Elsevier Science B.V. All rights reserved.