Corning Incorporated

University of Missouri

Soitec

Alexander Usenko

Nadia Ben Mohamed

Daniel Delprat

Jeffrey Scott Cites

Anthony M Caruso

Steven Lawrence Bellinger

Ta-Ko Chuang

Process flow for a stacked power diode and design of the resulting diode is disclosed. Blanket epitaxy over heavy doped wafers is performed. By controlling dopant addition during epitaxy, desired n-type, diode base, and p-type doping profiles and thicknesses achieved. V-groove pattern if formed on wafers by depositing mask film, lithography and anisotropic etch. Islands surrounded by V-grooves define individual diodes. V-grooves serve as side insulation. Next, oxidation step passivates V-grooves. Further, the mask film is stripped to open diode contact areas on both sides of wafers. Next high melting point metal and low melting point metal films are selectively electroplated on all open silicon surfaces. Stacking is performed on wafer level by bonding of desired wafer count by solid-liquid interdiffusion process. Wafer stacks are sawed into individual stacked diode dies along outer slopes of V-grooves. Final stacked devices can be used as DSRD—drift step recovery diodes. Compared to DSRDs made by known methods, better fabrication yield and higher pulse power electrical performance is achieved.

Stacked diode with side passivation and method of making the same

A direct wafer bonding process for joining GaN and silicon substrates involves pre-treating each of the wafers in an ammonia plasma in order to render the respective contact surfaces ammophilic. The GaN substrate and the silicon substrate may each comprise single crystal wafers. The resulting hybrid semiconductor structure can be used to form high quality, low cost LEDs.

Gallium nitride to silicon direct wafer bonding

A semiconductor-on-glass substrate having a relatively stiff (e.g. relatively high Young's modulus of 125 or higher) stiffening layer or layers placed between the silicon film and the glass in order to eliminate the canyons and pin holes that otherwise form in the surface of the transferred silicon film during the ion implantation thin film transfer process. The new stiffening layer may be formed of a material, such as silicon nitride, that also serves as an efficient barrier against penetration of sodium and other harmful impurities from the glass substrate into the silicon film.

Semiconductor on glass substrate with stiffening layer

Growing community of inventors

Painted Post, NY, United States of America

Alexander Usenko