Compound semiconductor element resistible to high voltage

Abstract

A compound semiconductor element is provided which electrically connects an electrode 3 formed on one main surface 2 a of a compound semiconductor region 2 with a substrate 5 to fix an electric potential of substrate 5 at an electric potential of electrode 3 , thereby preventing fluctuation in electric potential of substrate 5 under the changing operating condition of the device for stabilization in electric property of the device. Also, formed between compound semiconductor region 2 and substrate 5 is an insulating layer 6 for blocking a leakage current which may flow longitudinally between one main surface 2 a of compound semiconductor region 2 and substrate 5 so that sufficiently high withstand voltage property can be given between compound semiconductor region 2 and substrate 5 . In addition, formed in compound semiconductor region 2 is a notch 14 which extends in the thickness direction from main surface 2 a of compound semiconductor region 2 and reaches at least insulating layer 6 , and an insulating protective layer 15 covers a side surface of a conductive film 7 exposed to the notch 14 to prevent occurrence of electric discharge between conductive film 7 and substrate 5 for stable and high withstand voltage.

1 - 11 . (canceled) 
   
   
       12 . A compound semiconductor element comprising a base plate of an electrically conductive material, a compound semiconductor region formed on a main surface of said base plate, and electrodes formed on one main surface of said compound semiconductor region for electrical connection of one of said electrodes to said base plate,
 a notch being formed to extend in the thickness direction from one main surface of said compound semiconductor region to a boundary surface between said compound semiconductor region and base plate, and   an insulating protective layer covering a side surface of said compound semiconductor region exposed to said notch,   wherein said insulating protective layer is formed of a silicon nitride film, and   one main surface of said compound semiconductor region is coated with an insulating protective film of silicon oxide.   
   
   
       13 . The compound semiconductor element of  claim 12 , wherein said notch extends beyond the boundary surface between said base plate and compound semiconductor region toward the other main surface of said base plate,
 said insulating protective layer is formed across said boundary surface on exposed side surfaces of said compound semiconductor region and base plate to said notch, and   said insulating protective layer has an extension in contact to an upper surface of said base plate exposed to a bottom surface of said notch.   
   
   
       14 . The compound semiconductor element of  claim 12 , wherein said notch is formed into a loop around an outer periphery of the compound semiconductor element, and
 said insulating protective layer covers a side surface of said notch.   
   
   
       15 . The compound semiconductor element of  claim 12 , wherein said base plate is a silicon monocrystalline base plate, and
 said compound semiconductor region is of a gallium nitride compound.   
   
   
       16 . The compound semiconductor element of  claim 12 , wherein the element is a semiconductor device for high frequency and high power. 
   
   
       17 . The compound semiconductor element of  claim 12 , wherein said insulating protective film of silicon oxide covers one main surface of said compound semiconductor region between two electrodes. 
   
   
       18 . The compound semiconductor element of  claim 12 , wherein the insulating protective layer seals the side surface of the compound semiconductor region formed on a substrate of silicon monocrystallization and can prevent generation of electric discharge between the substrate and the compound semiconductor region. 
   
   
       19 . The compound semiconductor element of claim  1 , comprising a wiring or lead wire for electrically connecting between an anode electrode of the electrodes and the base plate.