Metallization structure for high power microelectronic devices

摘要

A semiconductor device structure is disclosed that includes a wide-bandgap semiconductor portion selected from the group consisting of silicon carbide and the Group III nitrides. An interconnect structure is made to the semiconductor portion, and the interconnect structure includes at least two diffusion barrier layers alternating with two respective high electrical conductivity layers. The diffusion barrier layers have a coefficient of thermal expansion different from and lower than the coefficient of thermal expansion of the high electrical conductivity layers. The difference in the respective coefficients of thermal expansions are large enough to constrain the expansion of the high conductivity layers but less than a difference that would create a strain between adjacent layers that would exceed the bond strength between the layers.

主权项

1. A semiconductor device structure comprising:
a wide-bandgap semiconductor portion selected from the group consisting of silicon carbide and Group III nitrides; an interconnect structure to said wide-bandgap semiconductor portion, said interconnect structure comprising a plurality of diffusion barrier layers alternating with a plurality of high electrical conductivity layers, the plurality of diffusion barrier layers and the plurality of high electrical conductivity layers comprising:
a first diffusion barrier layer on a surface of a portion of the semiconductor device structure selected from the group consisting of said wide-bandgap semiconductor portion, an ohmic contact, a Schottky contact, and a dielectric layer;a first high electrical conductivity layer on a surface of the first diffusion barrier layer opposite the portion of the semiconductor device structure;a second diffusion barrier layer on a surface of the first high electrical conductivity layer opposite the first diffusion barrier layer;a second high electrical conductivity layer on a surface of the second diffusion barrier layer opposite the first high electrical conductivity layer;a third diffusion barrier layer on a surface of the second high electrical conductivity layer opposite the second diffusion layer; a first adhesion layer, wherein the first diffusion barrier layer is directly on the first adhesion layer; said plurality of diffusion barrier layers having a coefficient of thermal expansion different from and lower than a coefficient of thermal expansion of said plurality of high electrical conductivity layers; and the difference in the respective coefficients of thermal expansions being large enough to constrain the expansion of said plurality of high electrical conductivity layers but less than a difference that would create a strain between adjacent diffusion and high electrical conductivity layers that would exceed a bond strength between the adjacent diffusion and high electrical conductivity layers.