Method for bonding compound semiconductor wafers to create an ohmic interface
First Claim
1. A semiconductor device having at least one wafer bonded unipolar interface, the wafer bonded unipolar interface formed by applying uniaxial pressure at a predefined temperature, the wafer bonded unipolar interface passing current from a first semiconductor layer to a second semiconductor layer with a minimal voltage drop, at least one of the first and second semiconductor layers comprising a compound semiconductor, the surface misorientation of the layers being less than 6 degrees in magnitude and the rotational misalignment of the crystallographic directions in the plane of the wafer bonded unipolar interface being less than 20 degrees in magnitude, for a predefined crystal orientation and all crystallographically equivalent orientations between the first and second semiconductor layers.
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Abstract
A method for forming an ohmic interface between unipolar (isotype) compound semiconductor wafers without a metallic interlayer and the semiconductor devices formed with these ohmic interfaces are disclosed. The ohmic interface is formed by simultaneously matching the crystallographic orientation of the wafer surfaces and the rotational alignment within the surfaces of the two wafers and then subjecting them to applied uniaxial pressure under high temperatures to form the bonded ohmic interface. Such an ohmic interface is required for the practical implementation of devices wherein electrical current is passed from one bonded wafer to another.
110 Citations
5 Claims
- 1. A semiconductor device having at least one wafer bonded unipolar interface, the wafer bonded unipolar interface formed by applying uniaxial pressure at a predefined temperature, the wafer bonded unipolar interface passing current from a first semiconductor layer to a second semiconductor layer with a minimal voltage drop, at least one of the first and second semiconductor layers comprising a compound semiconductor, the surface misorientation of the layers being less than 6 degrees in magnitude and the rotational misalignment of the crystallographic directions in the plane of the wafer bonded unipolar interface being less than 20 degrees in magnitude, for a predefined crystal orientation and all crystallographically equivalent orientations between the first and second semiconductor layers.
Specification