| 摘要 |
PURPOSE:To contrive to improve the characteristic of a FET by a method wherein the high density layer of the source side is made close to a gate electrode, and then the high density layer of the drain side is arranged in self- alignment at an arbitrary length from the gate electrode. CONSTITUTION:Three layer masks 23 of resist 23a, SiO2 23b, and resistor 23c are applied on a GaAs substrate 21. When ions are implanted 31 at the angle of incidence theta=10 deg.-80 deg., the shade of tXtantheta is produced on the drain side, resulting in the formation of a source 24 and a drain 25 in the case that the thickness of the mask is t. Next, the contact between the gate electrode and the source 24 is prevented by etching the resist 23a by approx. 1mum on the side surface. Then, it is covered with SiO2 26, and then the masks 23 are removed. After the layers 24 and 25 are activated by heat treatment, ohmic electrodes 27 and 28 and the Schottky junction gate electrode 29 are added. This constitution enables to reduce source resistance, shorten the gate length, and obtain a FET wherein the drain withstand voltage is improved. |
