Abstract A field effect transistor comprising a compound semiconductor substrate, a source and a drain electrodes disposed on a compound semiconductor substrate, a gate electrode disposed therebetween, and a layer for reducing the surface levels formed on the surface of the substrate at least between the gate and the drain electrodes. The field effect transistor is produced by a process comprising steps of producing a gate electrode on an active layer which is produced by ion implantation into the semiconductor substrate, producing a source and a drain region by implanting impurity into the entire surface of the substrate using the gate electrode as a mask, producing ohmic electrodes on the source and the drain regions of the substrate, producing a layer for reducing localized surface levels which exists at that region by treating the surface of the substrate at least between the gate and the drain electrodes using predetermined reactive solution or gas, and producing a protecting film on the entire surface of the wafer. Therefor, the field effect transistor having a high gate-drain breakdown voltage is obtained without reducing the yield. This FET can be applied to high output analog integrated circuit.
A field effect transistor comprising: a compound semiconductor substrate; a source and a drain electrodes disposed on said compound semiconductor substrate; a gate electrode disposed on said compound semiconductor substrate between said source and said drain electrodes; and a layer for reducing the surface states formed on the surface of said substrate at least between said gate and said drain electrodes so as to reduce localized surface levels which exist at that region.
Claim 2
Dependent Claim
18 words
The field effect transistor of claim 1 wherein said layer for reducing surface levels is a sulfurized layer.
Claim 3
Independent Claim
142 words
A method for producing a field effect transistor comprising a source and a drain electrodes disposed on a compound semiconductor substrate and a gate electrode disposed on said compound semiconductor substrate between said source and said drain electrodes, comprising steps of: producing a gate electrode on an active layer which is produced by ion implantation to said semiconductor substrate; producing a source and a drain region by implanting impurity into the entire surface of said substrate using said gate electrode as a mask; producing ohmic electrodes on said source and said drain regions of said substrate, producing a layer for reducing localized surface levels by treating the surface of said substrate at least one of between said ohmic electrodes and said gate electrode using predetermined reactive solution or reactive gas; and producing a protecting film on the entire surface of the wafer.
Claim 4
Dependent Claim
19 words
The method of claim 3 wherein said predetermined reactive solution or reactive gas is solution or gas containing sulfur.
Claim 5
Independent Claim
129 words
A method for producing a field effect transistor comprising a source and a drain electrodes disposed on a compound semiconductor substrate and a gate electrode disposed on said compound semiconductor substrate between said source and said drain electrodes, comprising steps of: producing a gate electrode on an active layer which is produced by ion implantation into said semiconductor substrate; producing a source and a drain region by implanting impurity into the entire surface of said substrate using said gate electrode as a mask; producing a layer for reducing localized surface levels by treating the surface of said substrate using predetermined reactive solution or reactive gas; producing ohmic electrodes on said source and drain regions of said substrate; and producing a protecting film on the entire surface of the wafer.
Claim 6
Dependent Claim
19 words
The method of claim 5 wherein said predetermined reactive solution or reactive gas is solution or gas containing sulfur.
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