Method for production of compound semicondutor devices

A method for producing compound semiconductor devices which comprises:

• depositing sidewall material consisting of a first insulating material in a tapered shape adjacent to each side of Schottky junction electrodes made of refractory metal on a semiconductor substrate;
• selectively forming an N or P type active layer partially on said semiconductor top surface, said selectively forming excludes the portions containing said Schottky junction electrodes;
• covering the entire surface of said semiconductor substrate with a second insulating film;
• coating a photoresist on said second insulating film;
• providing a continuous opening in said photoresist above predetermined portions of said N or P type active layer and above said Schottky junction electrodes;
• removing the said second insulating film exposed at said opening using said photoresist as a mask;
• depositing an ohmic electrode material on the entire surface of said semiconductor substrate;
• lifting-off the ohmic electrode portions, which are coated on other than said opening by removing said photoresist;
• and alloying said ohmic electrode to the N or P type active layer and Schottky junction electrodes, thereby providing a direct junction between said N or P type active layer and said Schottky electrodes without using conventional contact holes and wiring, wherein the ohmic electrode overriding the Schottky junction electrode tapered sidewalls enables a high yield connection to be achieved.

A method for producing compound semiconductor devices which comprises:

• forming Schottky junction electrodes by depositing refractory metal over an entire semi-insulating GaAs substrate and applying photoresist and dry etching;
• depositing first insulating material on the said substrate and Schottky junction electrodes, and anisotropic dry etching to form tapered side walls consisting of said first insulating material adjacent to each side of the said Schottky junction electrodes;
• selectively forming an N or P type active layer partially on the top surface of said substrate by ion implantation with photoresist as the mask;
• covering the entire top surface of said semiconductor substrate with a second insulating film, said second insulating film consists of a material for allowing selective isotropic etching with reference to said first insulating material;
• coating a photoresist on said second insulating film;
• providing at least one continuous opening in said photoresist above predetermined portions of said N or P type active layer and above said Schottky junction electrodes;
• removing the said second insulating film at said opening using anisotropic dry etching and isotropic wet etching with said photoresist as a mask;
• depositing an ohmic electrode material on the entire top surface of said substrate;
• lifting off ohmic electrode portions which are coated on other than said opening by removing said photoresist;
• and alloying said ohmic electrode to the N or P type active layer and Schottky junction electrodes, thereby providing a direct junction between said N or P type active layer and said Schottky junction electrodes without using conventional contact holes and wiring, wherein the ohmic electrode overriding the Schottky junction electrodes tapered side walls enables a high yield connection to be achieved.