Back to results
US 2026/0239656 A1Published application
Vertical gan moshemts with improved performance structures
AssigneesNami MOS CO., LTD., Mosel Vitelic, Inc.
InventorsFu-Yuan HSIEH, Lin XU
Life of this patent
Estimating the term…
Abstract
An integrated circuit comprising a vertical GaN MOSHEMT and a GaN super barrier rectifier (SBR) electrodes disposed in a gate trench of an unit cell. A first channel region of the GaN HEMT is formed along a first sidewall of the gate trench while a second channel region of the GaN SBR is formed along a first portion of a second sidewall opposite to the first sidewall of the gate trench. A source metal connects with the heterojunctions, body regions of the GaN HEMT and GaN SBR, and the gate electrode of the GaN SBR through a source contact trench, and further connects with a P-shield (PS) region below the gate trench through a grounded P (GP) region along a second portion of the second sidewall of the gate trench.
Claims20
A nitride semiconductor device, comprising:
- at least three epitaxial layers including a top, a middle and a bottom epitaxial layers of a first conductivity type, grown on a substrate;
- said top epitaxial layer having a different band gap from that of said middle epitaxial layer of said first conductivity type;
- at least one heterojunction formed at an interface between said top and middle epitaxial layers creating a two-dimensional electron gas (2DEG) thus allowing current flow thereof;
- a body region of second conductivity type formed at a top portion of said bottom epitaxial layer connecting with a body contact region of said second conductivity type;
- a gate trench penetrating through said top and middle epitaxial layers, and said body region, and stopping in said bottom epitaxial layer;
- a source contact trench penetrating through said top and middle epitaxial layers, and said body contact regions, and stopping in said bottom epitaxial layer;
- a gate electrode disposed into said gate trench, and laterally isolated from said at least three epitaxial layers with a gate oxide on sidewalls of said gate trench;
- at least one pair of first P-shield (PS1) regions of said second conductivity type formed in said bottom epitaxial layer of said first conductivity type, and separated from each other in a horizontal direction by a Junction Field Effect Transistor (JFET) region of said first conductivity type with a doping concentration higher than that of said bottom epitaxial layer, wherein said each of said one pair of PS1 regions surrounding a bottom region of said source contact trench and connecting with said body contact regions;
- and
- a contact metal plug filling into said source contact trench connecting said heterojunction and said body contact regions with a source metal.
7 more elements
The nitride semiconductor device of claim1, comprising three epitaxial layers of AlXGaYN/GaN/AlXGaYN on top of said body region, and two heterojunctions formed at the two interfaces of AlXGaYN/GaN/AlXGaYN epitaxial layers above said body region, wherein X=1 and Y=1, or 0<X<1 and Y=1−X.
An integrated circuit comprising:
- a GaN MOSHEMT and a GaN SBR integrated in each unit cell;
- at least three epitaxial layers including a top, a middle and a bottom epitaxial layers of a first conductivity type, grown on a substrate;
- said top epitaxial layer of said first conductivity type having a different band gap from that of said middle epitaxial layer of said first conductivity type;
- at least one heterojunction formed at an interface between said top and said middle epitaxial layers creating a two-dimensional electron gas (2DEG) thus allowing current flow thereof;
- a first body region of said GaN MOSHEMT and a second body region of said GaN SBR of said second conductivity type formed at a top portion of said bottom epitaxial layer;
- a gate trench penetrating through said top and middle epitaxial layers, and said first and second body regions, and stopping in said bottom epitaxial layer;
- a source contact trench penetrating through said top and middle epitaxial layers, and body contact regions of said second conductivity type, and stopping in said bottom epitaxial layer;
- a contact metal plug filling into said source contact trench connecting said heterojunction and body contact regions with a source metal.
- said GaN MOSHEMT further comprising:
- a first gate electrode disposed into said gate trench, and laterally isolated from said at least three epitaxial layers with a first gate oxide on a first sidewall of said gate trench;
- said first gate electrode surrounded with a first insulating film on a bottom of said gate trench and said first insulating film having a thickness greater than that of said first gate oxide;
- a first channel region formed in said first body region along said first sidewall of said gate trench;
- said GaN SBR further comprising:
- a second gate electrode disposed in said gate trench side by side with said first gate electrode, and isolated from said first gate electrode with an inter-polysilicon oxide (IPO);
- said second gate electrode laterally isolated from said at least three epitaxial layers with a second gate oxide on a second sidewall of said gate trench having an oxide thickness less than that of said first gate oxide;
- said second gate electrode surrounded with a second insulating film on a bottom region of said gate trench and said second insulating film having a thickness greater than that of said second gate oxide;
- and said first insulating film having a thickness greater than that of said second insulating film;
- a second channel region formed in said second body region along said second sidewall of said gate trench opposite to said first sidewall, wherein said second channel region has a channel length shorter than that of said first channel region;
- a short channel implant (SCI) region of said first conductivity type formed along said second sidewall and surrounding said second gate electrode;
- said second gate electrode shorted to said source metal through a gate contact of said GaN SBR;
- a current spreading layer (CSL) of said first conductivity type formed at a top portion of said bottom epitaxial layer below said first and second body regions with a doping concentration higher than that of said bottom epitaxial layer;
- and
- a first P-shield (PS1) region of said second conductivity type surrounding a bottom region of said source contact trench and connecting with said body contact regions.
20 more elements
An integrated circuit comprising:
- a GaN MOSHEMT and a GaN SBR disposed in a gate trench of each unit cell;
- at least three epitaxial layers including a top, a middle and a bottom epitaxial layers of a first conductivity type, grown on a substrate;
- said top epitaxial layer of said first conductivity type having a different band gap from that of said middle epitaxial layer of said first conductivity type;
- at least one heterojunction formed at an interface between said top and said middle epitaxial layers creating a two-dimensional electron gas (2DEG) thus allowing current flow thereof;
- a first body region of said GaN MOSHEMT of a second conductivity type formed at a top portion of said bottom epitaxial layer;
- a gate trench penetrating through said top and middle epitaxial layers, and said first body region, and stopping in said bottom epitaxial layer;
- a source contact trench penetrating through said top and middle epitaxial layers, and body contact regions, and stopped in said bottom epitaxial layer;
- a contact metal plug filling into said source contact trench connecting said heterojunction, and said body contact regions of said second conductivity type with a source metal.
- a current spreading layer (CSL) region of said first conductivity type formed at a top portion of said bottom epitaxial layer below said first and second body regions with a doping concentration higher than that of said bottom epitaxial layer;
- a first P-shield (PS1) region of said second conductivity type surrounding bottoms of said source contact trench;
- a gate electrode disposed in an upper portion of said gate trench, and a shielded gate electrode disposed below said gate electrode and isolated from said gate electrode by an inter-poly oxide (IPO) layer;
- said gate electrode acting as a first gate electrode laterally isolated from said epitaxial layer by a first gate oxide of said GaN MOSHEMT on first sidewall of said gate trench, and said shielded gate electrode acting as a second gate electrode vertically isolated from said epitaxial layer by a second gate oxide of said GaN SBR on said bottom region of said gate trench, wherein said second gate oxide has a thickness less than that of said first gate oxide;
- said GaN MOSHEMT further comprising:
- a first channel region of said GaN MOSHEMT formed in said first body region along said first sidewall of said gate trench;
- said GaN SBR further comprising:
- a second body region and a first source region surrounding a second sidewall of said gate trench, and a portion of said bottom region of said gate trench adjacent to said second sidewall, wherein said second sidewall is opposite to said first gate trench sidewall;
- a second channel region formed in a second body region along said bottom region of said gate trench, wherein said second channel region has a channel length shorter than that of said first channel region;
- and
- said second gate electrode shorted to said source metal through a shielded gate contact of said GaN SBR.
16 more elements
Dependencies are inferred from the claim text.