| 摘要 |
The conventional compound semiconductor switching device is prone to have a large chip size as the gate width needs to be large for achieving a low insertion loss and the separation between the connecting pad and the circuit wiring needs to be larger than 20 µm for obtaining a proper isolation between them. The overall chip size is reduced, first, by reducing the gate width (Wg) of the switching FET operating at frequencies above 2.4 GHz to 700 µm or smaller together with the omission of the shunt FET, and, then, by reducing the separation between the connecting pad and the circuit wiring to 20 µm or smaller. This reduction of the separation is made possible by the introduction of an insulating film and a impurity region (40) between the outermost portion of the connecting pad and the substrate for preventing the extension of the depletion layer. The manufacturing method of this device does not need any additional processing step for accommodating the above structure, and is capable of producing a device having a size of one fifth of the conventional device. Further it allows for removing of an silicon nitride film from an area underneath the connection pad, thereby improving ease of manufacture and quality of the devices manufactured. |
