Abstract: A high electron mobility transistor (HEMT) device comprising a substrate, a plurality of semiconductor layers provided on the substrate, and a source terminal, a drain terminal and at least one gate terminal provided on the plurality of semiconductor layers. The HEMT also includes a metal ring formed on the plurality of semiconductor layers around the source terminal, the drain terminal and the at least one gate terminal, where the metal ring operates to shift the pinch-off voltage of the device. In one embodiment, the metal ring includes an ohmic portion and an electrode portion, where both the ohmic portion and the electrode portion include a lower titanium layer, a middle platinum layer and an upper gold layer.

Abstract: A method for fabricating a double-recess gate structure for an FET device that includes providing a semiconductor wafer having a plurality of semiconductor layers and depositing an EBL resist layer on the wafer. The method also includes patterning the EBL resist layer to form an opening in the EBL resist layer and performing a first wet etch to form a first recess in the wafer. The method further includes depositing a dielectric layer over the EBL resist layer and into the first recess and performing a dry etch to remove a portion of the dielectric layer in the first recess. The method also includes performing a second wet etch through the opening in the dielectric layer to form a second recess, and depositing a gate metal layer in the first and second recesses and in the opening in the EBL resist layer to form a gate terminal.

Abstract: In a method of forming a semiconductor device on a semiconductor substrate (100), a photoresist layer (102) is deposited on the semiconductor substrate; a window (106) is formed in the photoresist layer (102) by electron beam lithography; a conformal layer (108) is deposited on the photoresist layer (102) and in the window (106); and substantially all of the conformal layer (108) is selectively removed from the photoresist layer (102) and a bottom portion of the window to form dielectric sidewalls (110) in the window (106).

Abstract: In a method of forming a semiconductor device on a semiconductor substrate (100), a photoresist layer (102) is deposited on the semiconductor substrate; a window (106) is formed in the photoresist layer (102) by electron beam lithography; a conformal layer (108) is deposited on the photoresist layer (102) and in the window (106); and substantially all of the conformal layer (108) is selectively removed from the photoresist layer (102) and a bottom portion of the window to form dielectric sidewalls (110) in the window (106).

Abstract: In a method of forming a semiconductor device on a semiconductor substrate (100), a photoresist layer (102) is deposited on the semiconductor substrate; a window (106) is formed in the photoresist layer (102) by electron beam lithography; a conformal layer (108) is deposited on the photoresist layer (102) and in the window (106); and substantially all of the conformal layer (108) is selectively removed from the photoresist layer (102) and a bottom portion of the window to form dielectric sidewalls (110) in the window (106).

Abstract: In a method of forming a semiconductor device on a semiconductor substrate (100), a photoresist layer (102) is deposited on the semiconductor substrate; a window (106) is formed in the photoresist layer (102) by electron beam lithography; a conformal layer (108) is deposited on the photoresist layer (102) and in the window (106); and substantially all of the conformal layer (108) is selectively removed from the photoresist layer (102) and a bottom portion of the window to form dielectric sidewalls (110) in the window (106).