Abstract: A method for fabricating a dual gate structure for JFETs and MESFETs and the associated devices. Trenches are etched in a semiconductor substrate for fabrication of a gate structure for a JFET or MESFET. A sidewall spacer may be formed on the walls of the trenches to adjust the lateral dimension for a first gate. Following the formation of the first gate by implantation or deposition, a buffer region is implanted below the first gate using a complementary dopant and a second sidewall spacer with a thickness that may be the same or greater than the thickness of the first sidewall spacer. Subsequent to the buffer implant, a second gate is implanted beneath the buffer layer using a third sidewall spacer with a greater thickness than the first sidewall spacer.

Abstract: A protection device for integrated circuits. A complementary well is fabricated in a semiconductor substrate. An enhancement mode junction field effect transistor (JFET) is fabricated in the complementary well. An interface bonding pad is fabricated above the JFET. A source contact is also fabricated in the well. The gate and drain of the JFET are coupled to the interface bonding pad and the source of the JFET is coupled to the substrate.

Abstract: A method for fabricating a guard ring structure for JFETs and MESFETs. Trenches are etched in a semiconductor substrate for fabrication of a gate structure for a JFET or MESFET. At time the gate trenches are etched, concentric guard ring trenches are also etched. The process used to fabricate the gate p-h junction or Schottky barrier at the bottom of the gate trenches is also used to fabricate the guard ring at bottom of the guard ring trenches. The separation between the guard ring trenches is 1.0 to 3.0 times greater than the separation between the gate trenches.