| 摘要 |
PROBLEM TO BE SOLVED: To reduce the effect of a parasitic transistor and restrain a leak current between source and drain, by forming, between element forming regions, a second insulating film which is connected with a first insulating film and has a thickness greater than the thickness of the element forming regions. SOLUTION: On the periphery of an element forming region 4 isolated from a silicon semiconductor layer 3, a silicon oxide film (first insulating film) 5 having the same height is embedded. Where the space between the adjacent element forming regions 4 is narrow, only the oxide film 5 is embedded. However, where the space between the element forming regions 4 is large, a silicon isolation oxide film (second insulating film) 6 having a greater height and a greater thickness than the element forming region 4 is formed. Since the embedded oxide film 5 is formed in such a manner as to realize smooth surface connection with the height sequentially increasing from the element forming region 4 toward the isolation oxide film 6, no short circuit is generated in the gate. Also, since the thickness of the isolation oxide film 6 may be increased, the parasitic capacitance may be reduced. |
