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US 8,569,765 B2Granted
MOSFET-Schottky rectifier-diode integrated circuits with trench contact structures
AssigneeForce Mos Technology Co., Ltd.
InventorFu-Yuan Hsieh
Life of this patent
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Abstract
A trench MOSFET device with embedded Schottky rectifier, Gate-Drain and Gate-Source clamp diodes on single chip is formed to achieve device shrinkage and performance improvement. The present semiconductor devices achieve low Vf and reverse leakage current for embedded Schottky rectifier, have overvoltage protection for Gate-Source clamp diode and avalanche protection for Gate-Drain clamp diode.
Claims30
An integrated circuit comprising:
- a substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping concentration than said substrate;
- a trench MOSFET comprising a plurality of trenched gates surrounded by a source region of said first conductivity type encompassed in a body region of a second conductivity type;
- each said trenched gate comprising a conductive material padded by a gate oxide layer filled in a gate trench, wherein said gate oxide layer having a thick bottom oxide on bottom surface of said gate trench with a thickness greater than sidewall oxide along sidewall of said gate trench;
- a Schottky rectifier extending into said epitaxial layer and having a Schottky barrier layer lined in a trenched anode contact filled with a contact metal plug;
- a Gate-Drain clamp diode comprising multiple back to back poly-silicon Zener diodes with alternating doped regions of said first conductivity type next to said second conductivity type, connected with a gate metal on one side, and with a drain metal on another side through a plurality of metal stripes cross over a termination area;
- and
- a Gate-Source clamp diode comprising multiple back to back poly-silicon Zener diodes with alternating doped regions of said first conductivity type next to said second conductivity type, connected with said gate metal on one side, and with a source metal on another side.
5 more elements
An integrated circuit comprising:
- a substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping concentration than said substrate;
- a trench MOSFET comprising a plurality of trenched gates surrounded by a source region of said first conductivity type encompassed in a body region of a second conductivity type;
- each said trenched gate comprising a conductive material padded by a gate oxide layer filled in a gate trench, wherein said gate oxide layer having a thick bottom oxide on bottom surface of said gate trench with a thickness greater than sidewall oxide along sidewall of said gate trench;
- a Schottky rectifier extending into said epitaxial layer and having a Schottky barrier layer lined in a trenched anode contact filled with a contact metal plug;
- and
- a Gate-Source clamp diode comprising multiple back to back poly-silicon Zener diodes with alternating doped regions of said first conductivity type next to said second conductivity type, connected with a gate metal on one side, and with a source metal on another side.
4 more elements
An integrated circuit comprising:
- a substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping concentration than said substrate;
- a trench MOSFET comprising a plurality of trenched gates surrounded by a source region of said first conductivity type encompassed in a body region of a second conductivity type;
- each said trenched gate comprising a conductive material padded by a gate oxide layer filled in a gate trench, wherein said gate oxide layer having a thick bottom oxide on bottom surface of said gate trench with a thickness greater than sidewall oxide along sidewall of said gate trench;
- a Schottky rectifier extending into said epitaxial layer and having a Schottky barrier layer lined in a trenched anode contact filled with a contact metal plug;
- and
- a Gate-Drain clamp diode comprising multiple back to back poly-silicon Zener diodes with alternating doped regions of said first conductivity type next to said second conductivity type, connected with a gate metal on one side, and with a drain metal on another side through a plurality of metal stripes cross over a termination area.
4 more elements
An integrated circuit comprising:
- a substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping concentration than said substrate;
- a trench MOSFET comprising a plurality of trenched gates surrounded by a source region of said first conductivity type encompassed in a body region of a second conductivity type;
- each said trenched gate comprising a conductive material padded by a gate oxide layer filled in a gate trench, wherein said gate oxide layer having a thick bottom oxide on bottom surface of said gate trench with a thickness greater than sidewall oxide along sidewall of said gate trench;
- a Gate-Drain clamp diode comprising multiple back to back poly-silicon Zener diodes with alternating doped regions of said first conductivity type next to said second conductivity type, connected with a gate metal on one side, and with a drain metal on another side through a plurality of metal stripes cross over a termination area;
- and
- a Gate-Source clamp diode comprising multiple back to back poly-silicon Zener diodes with alternating doped regions of said first conductivity type next to said second conductivity type, connected with said gate metal on one side, and with a source metal on another side.
4 more elements
An integrated circuit comprising:
- a substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping concentration than said substrate;
- a trench MOSFET comprising a plurality of trenched gates surrounded by a source region of said first conductivity type encompassed in a body region of a second conductivity type;
- each said trenched gate comprising a conductive material padded by a gate oxide layer filled in a gate trench, wherein said gate oxide layer having a thick bottom oxide on bottom surface of said gate trench with a thickness greater than sidewall oxide along sidewall of said gate trench;
- a Gate-Source clamp diode comprising multiple back to back poly-silicon Zener diode with alternating doped regions of said first conductivity type next to said second conductivity type, connected with a gate metal on one side, and with a source on another side.
2 more elements
An integrated circuit comprising:
- a substrate of a first conductivity type;
- an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping concentration than said substrate;
- a trench MOSFET comprising a plurality of trenched gates surrounded by a source region of said first conductivity type encompassed in a body region of a second conductivity type;
- each said trenched gate comprising a conductive material padded by a gate oxide layer filled in a gate trench, wherein said gate oxide layer having a thick bottom oxide on bottom surface of said gate trench with a thickness greater than sidewall oxide along sidewall of said gate trench;
- a Gate-Drain clamp diode comprising multiple back to back poly-silicon Zener diodes with alternating doped regions of said first conductivity type next to said second conductivity type, connected with a gate metal on one side, and with a drain metal on another side through a plurality of metal stripes cross over a termination area.
2 more elements
Dependencies are inferred from the claim text.