| 摘要 |
PURPOSE:To obtain an FET with an excellent heat-resisting feature by a method wherein a high barrier is realized by using Al.WSi containing a very small quantity of Al as the material for a gate electrode. CONSTITUTION:Si ions 7 are driven into a semi-insulating GaAs substrate 1 for the formation of a channel 2. The surface is then coated with SiO2 before annealing is accomplished for activation. The SiO2 is removed and a coating is formed of WAlxSiy by sputtering. When W is one, x should be not more than 0.08 and y between 0.5-1.4. RIE is accomplished by using CF4 gas for the WAlxSiy to be patterned into a gate electrode 8. Next, the electrode 8 and a resist 9 work together as a mask and implantation is accomplished of Si ions 10 for the formation of source/drain layer 11, 11'. The resist 9 is removed, a capping film is provided of SiO2, and then annealing is effected. Finally, electrodes 12, 13 are built of Au/Ni/AuGe. Heat treatment is done for the metals to develop into an alloy, to complete the device. A Schottky barrier in a device of this design is as high as 0.8V. An FET of this design is provided with a gate electrode presensing high resistance to heat even when the gate electrode is built in relatively low vacuum. |
