| 摘要 |
<p>PURPOSE:To form properly TFTs of a constitution having a high mobility and a TFT of a constitution having low-leakage current characteristics according to their respective purposes and moreover, to form a CPU circuit and memory circuits on the same substrate by a method wherein at least one element among carbon, nitrogen, oxygen and silicon is added into the active layer of the first thin film transistor in a specified density by irradiating high-speed ions on the active layer. CONSTITUTION:N-channel TFTs for high-frequency low-power consumption of drivers, decoders, a CPU, memories and the others, N-channel TFTs for driver to drive high power and necessary P-channel TFTs are used for a semiconductor integrated circuit in addition to an N-channel TFT 11 constituting an active matrix circuit. Out of these TFTs, oxygen is added into an active layer of the TFT 11, which is arranged at each pixel electrode,in a density of 5X10<19> to 4X10<21> atomic cm<-3> and the TFT 11 is formed into a constitution having low-leakage current characteristics. Moreover, the concentrations of oxygen, nitrogen and carbon are set low in active layers of the other TFTs constituting peripheral circuits in a concentration of 1X19<19>cm<-3> or lower and the TETs are formed into a constitution having a high mobility.</p> |
