Method for fabricating a silicon-on-insulator voltage multiplier

Abstract

The present invention provides a method for fabricating a silicon-on-insulator voltage multiplier. The method comprises the steps of: forming a first silicon layer having a first concentration of a first dopant with a first polarity on a silicon wafer having a second concentration of a second dopant with a second polarity opposite the first polarity to create a diode junction; forming a second silicon layer on the first silicon layer, the second silicon layer having a third concentration of a third dopant having the first polarity, where the third concentration is greater than the first concentration of the first dopant; forming a silicon dioxide layer on the second silicon layer by thermal oxidation; bonding an insulating substrate to the silicon dioxide layer to create a bonded wafer, where the insulating substrate is selected from the group consisting of quartz, glass, sapphire, and silicon dioxide on silicon; thinning the silicon wafer to form a thinned silicon layer; etching the bonded wafer to form a plurality of separate diodes having sloped sidewalls and to expose selected regions of the insulating substrate; forming an insulating silicon layer on the selected regions of the insulating substrate and on the separate diodes; exposing selected regions of the thinned silicon layer and regions of the second silicon layer of each of the diodes; and forming metal interconnects between the exposed selected regions of the thinned silicon layer of one of the diodes with the silicon layer of another of the diodes.

We claim: 
     
       1. A bonded silicon-on-insulator diode circuit, comprising: a bulk insulating substrate; and   multiple diodes, each diode including: a silicon dioxide layer bonded to said insulating substrate;   a silicon layer conjoined with said silicon dioxide layer; and   a p-n diode junction formed in said silicon layer, said silicon layer being differential thermal expansion defect free.     
     
     
       2. The bonded silicon-on-insulator diode circuit of claim 1 wherein said insulating substrate includes a material selected from the group of sapphire, quartz, glass, and silicon dioxide on silicon. 
     
     
       3. A voltage multiplier diode circuit, comprising: a bulk insulating substrate; and   an electrical circuit formed on said bulk insulating substrate, said electrical circuit having a multiplicity of diodes and capacitors interconnected to form a voltage multiplier, each of said diodes including: a silicon dioxide layer bonded to said insulating substrate;   a silicon layer conjoined with said silicon dioxide layer; and   a p-n diode junction formed in said silicon layer, said silicon layer being differential thermal expansion defect free.     
     
     
       4. The voltage multiplier diode circuit of claim 3 wherein said insulating substrate includes a material selected from the group of sapphire, quartz, glass, and silicon dioxide on silicon.