Method of forming a gate contact

摘要

A method is provided for forming a gate contact for a compound semiconductor device. The gate contact is formed from a gate contact portion and a top or wing contact portion. The method allows for the tunablity of the size of the wing contact portion, while retaining the size of the gate contact portion based on a desired operational frequency. This is accomplished by providing for one or more additional conductive material processes on the wing contact portion to increase the cross-sectional area of the wing contact portion reducing the gate resistance, while maintaing the length of the gate contact portion to maintain the operating frequency of the device.

主权项

1. A method for forming a gate contact for a compound semiconductor device, the method comprising:
depositing a first photoresist material layer over a substrate; depositing a second photoresist material layer over the first photoresist material layer, the second photoresist material layer having a higher sensitivity to a photoresist development process than the first photoresist material layer; performing a photoresist development process to form a first via in the first photoresist material layer and a second larger via, overlying the first via, in the second photoresist material layer; performing a first conductive material deposition process to form a gate contact having a gate contact portion formed in the first via in contact with the substrate and a wing contact portion disposed over and in contact with the gate contact portion in the second larger via; stripping a conductive material layer that results from the first conductive material deposition process from the second photoresist material layer; performing an etch process, after the stripping of the conductive material, to remove additional portions of the second photoresist material layer from the second larger via to laterally extend the second larger via; and performing a second conductive material deposition process, after the performing of the etch process, to form an outer wing contact portion to increase the cross-sectional area of the wing contact portion, while maintaining the length of the gate contact portion.