Sagfet with buffer layers
First Claim
Patent Images
1. A composite buffer structure for GaAs semiconductor products on a GaAs substrate comprising:
- a semi-insulating GaAs substrate having a first major surface on a plane oriented up to about 20 degrees towards the (1,1,1)A plane from the (1,0,0) crystalline plane;
a first layer of epitaxial GaAs directly on said first major surface;
an AlAs/GaAs superlattice directly on said first layer;
a second layer of epitaxial GaAs directly on said superlattice;
a first AlGaAs layer having a first mole fraction of Al directly on said second layer;
a second AlGaAs layer having a second mole fraction of Al directly on said first AlGaAs layer, said second mole fraction being higher than said first mole fraction;
a third layer of epitaxial GaAs directly on said second AlGaAs layer.
2 Assignments
0 Petitions
Accused Products
Abstract
A composite buffer layer is formed with a layer of GaAs on a semi-insulating GaAs substrate. Next a short period superlattice is formed followed by another GaAs layer. A layer of GaAlAs is then provided such that the Ai content and no doping followed by an intrinsic GaAs layer. The intrinsic GaAs layer is the active layer which serves as a channel.
-
Citations
7 Claims
-
1. A composite buffer structure for GaAs semiconductor products on a GaAs substrate comprising:
-
a semi-insulating GaAs substrate having a first major surface on a plane oriented up to about 20 degrees towards the (1,1,1)A plane from the (1,0,0) crystalline plane; a first layer of epitaxial GaAs directly on said first major surface; an AlAs/GaAs superlattice directly on said first layer; a second layer of epitaxial GaAs directly on said superlattice; a first AlGaAs layer having a first mole fraction of Al directly on said second layer; a second AlGaAs layer having a second mole fraction of Al directly on said first AlGaAs layer, said second mole fraction being higher than said first mole fraction; a third layer of epitaxial GaAs directly on said second AlGaAs layer. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A semiconductor product including a composite buffer structure on a GaAs substrate comprising:
-
a semiconductor substrate having a first major surface misoriented up to about 10 degrees towards the (1,1,1) plane from the (1,0,0) plane; a first epitaxial layer of GaAs over said substrate; a superlattice of AlAs/GaAs over said first layer of GaAs; a second epitaxial layer of GaAs over said superlattice; a first AlGaAs layer over said second layer of GaAs, said first AlGaAs layer having a graded Al concentration and includes a top surface portion having a selected Al mole fraction; a second AlGaAs layer over said first AlGaAs layer, said second AlGaAs layer having a uniform concentration of Al at said selected mole fraction; a third layer of eiptaxial GaAs over said second AlGaAs layer.
-
Specification