Area-efficient gated diode structure and method of forming same

An integrated circuit comprising at least one gated diode, the at least one gated diode comprising:

• a semiconductor layer of a first conductivity type;
• an active region of a second conductivity type formed in the semiconductor layer proximate an upper surface of the semiconductor layer;
• at least one trench electrode extending substantially vertically through the active region and at least partially into the semiconductor layer;
• a first terminal electrically connected to the trench electrode;
• and
• at least a second terminal electrically connected to the active region;
• wherein the at least one gated diode is operative in one of at least a first mode and a second mode as a function of a voltage potential applied between the first and second terminals, the first mode being characterized by the creation of an inversion layer in the semiconductor layer substantially surrounding the trench electrode, the gated diode having a first capacitance in the first mode and a second capacitance in the second mode, the first capacitance being substantially greater than the second capacitance.

A method of forming a gated diode, the method comprising the steps of:

• forming an active region of a first conductivity type in a semiconductor layer of a second conductivity type, the active region being formed proximate an upper surface of the semiconductor layer;
• forming at least one trench electrode extending substantially vertically through the active region and at least partially into the semiconductor layer;
• forming a first terminal electrically connected to the trench electrode;
• and
• forming at least a second terminal electrically connected to the active region;
• wherein the gated diode is operative in one of at least a first mode and a second mode as a function of a voltage potential applied between the first and second terminals, the first mode being characterized by the creation of an inversion layer in the semiconductor layer substantially surrounding the trench electrode, the gated diode having a first capacitance in the first mode and a second capacitance in the second mode, the first capacitance being substantially greater than the second capacitance.