| 摘要 |
PURPOSE:To improve the accuracy of a threshold voltage by forming the chan nel directions of normally-ON and normally-OFF type FETs in one direction and the direction perpendicular to the one direction with respect to a crystal axis, thereby forming only by one ion implanting. CONSTITUTION:Ohmic regions 3 to become source and drain regions of FETs are formed on a (100) GaAs semi-insulating substrate 1 so that a channel length direction becomes the same as crystal axis 01-1 direction, a channel region is formed to be interposed between both ohmic regions, and ohmic region 3' and channel region 2' are formed in the same direction as a crystal axis (0-1-1) direction at the channel length direction. At this time, the region 3 to become the drain of the FET 7 and the region 3' to become the source of the FET 3 are formed on the same region. The regions 2, 2' are formed by one heat treatment as one ion implantation to obtain normally-OFF and normally-ON type FETs 8. |
