High density gallium nitride devices using island topology

摘要

A Gallium Nitride (GaN) series of devices—transistors and diodes are disclosed—that have greatly superior current handling ability per unit area than previously described GaN devices. The improvement is due to improved layout topology. The devices also include a simpler and superior flip chip connection scheme and a means to reduce the thermal resistance. A simplified fabrication process is disclosed and the layout scheme which uses island electrodes rather than finger electrodes is shown to increase the active area density by two to five times that of conventional interdigitated structures. Ultra low on resistance transistors and very low loss diodes can be built using the island topology. Specifically, the present disclosure provides a means to enhance cost/effective performance of all lateral GaN structures.

主权项

1. A nitride semiconductor device comprising:
a) a substrate; b) a nitride semiconductor layer formed on a main surface of the substrate, the nitride semiconductor layer having a channel region through which electrons drift in a direction parallel to the main surface; c) a plurality of first island electrodes and a plurality of second island electrodes formed on the nitride semiconductor layer, spaced apart from each other and arranged alternately to produce a multiplicity of two-dimensional active regions in the nitride semiconductor layer, wherein the first and second island electrodes are, respectively, source and drain electrodes of a multi-island transistor, or, anode and cathode electrodes of a multi-island diode; d) an insulating layer formed on the nitride semiconductor layer having a plurality of openings for connections to the first and second island electrodes and any common electrode connections areas; e) a plurality of ball or bump connections connected through the plurality of openings to either of respective first or second island electrodes; and wherein a plurality of through-substrate via connections are formed where the first or second island electrodes or common electrode connection areas are not connected using a ball or bump connections, a large single electrode common pad is provided on a side of the substrate opposite the main surface, and the plurality of through-substrate via connections provide connections from a top of the first or second island electrodes or from respective common electrode connection areas to the common pad.