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US 12,426,362 B2Granted
Latch-up free high voltage device
AssigneeHalo Microelectronics International
InventorsLijie Zhao, Kenneth Chung-Yin Kwok, Suming Lai, Zhao Fang
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Abstract
An apparatus includes a first drain/source region and a second drain/source region surrounded by an isolation ring formed over a substrate, the isolation ring formed being configured to be floating, and a first diode connected between the substrate and the isolation ring, wherein the first diode is a Schottky diode.
Claims17
An apparatus comprising:
- a first drain/source region, a second drain/source region and a third drain/source region formed inside a well region having a first conductivity type, wherein the well region is surrounded by an isolation ring having a second conductivity type, wherein the isolation ring is floating, and the second drain/source region is formed in a body region and between the first drain/source region and the third drain/source region, and wherein the second drain/source region and the body region have two different conductivity types;
- a buried layer having the second conductivity type formed between the well region and a substrate having the first conductivity type, wherein the buried layer is part of the isolation ring, and the substrate is in direct contact with the isolation ring and located below and outside of the isolation ring, while the well region is within the isolation ring;
- a third diode formed between the substrate and the buried layer, wherein an anode of the third diode is connected to the substrate and a cathode of the third diode is connected to the buried layer;
- and
- a first diode, wherein the first diode is a Schottky diode, and wherein an anode of the Schottky diode is a metal contact connected to a metal contact of the substrate through a suitable semiconductor interconnect device and a cathode of the Schottky diode is a region having the second conductivity type, and wherein the region is connected to the buried layer, and wherein:
- the cathode of the Schottky diode is an N-type region, and wherein:
- a first P-type well is formed in the N-type region;
- and
- a second P-type well is formed in the N-type region, and wherein:
- a portion of the N-type region between the first P-type well and the second P-type well is in direct contact with a the metal contact of the Schottky diode;
- the metal contact of the Schottky diode comprises an upper portion and a lower portion, and three sides of the upper portion is surrounded by the lower portion;
- a rightmost edge of the first P-type well is vertically aligned with a first sidewall of the upper portion;
- and
- a leftmost edge of the second P-type well is vertically aligned with a second sidewall of the upper portion.
11 more elements
A load switch comprising:
- a first transistor;
- and
- a second transistor being back-to-back connected to the first transistor, wherein:
- a drain of the first transistor, a drain of the second transistor and a shared source are formed in a well region and within an isolation ring, wherein the isolation ring is floating, and wherein the shared source is formed in a body region, and between the drain of the first transistor and the drain of the second transistor, and wherein the shared source and the body region have two different conductivity types, and wherein the isolation ring comprises a bottom comprising a buried layer, a first sidewall and a second sidewall, and wherein the first sidewall comprises a first high density N-type well rectangular in shape, a first N-type well formed in the first high density N-type well, and a first N+ region trapezoidal in shape and formed in the first N-type well, and wherein a lower portion of the first N-type well is trapezoidal in shape, and the second sidewall comprises a second high density N-type well rectangular in shape, a second N-type well formed in the second high density N-type well, and a second N+ region trapezoidal in shape and formed in the second N-type well, and wherein a lower portion of the second N-type well is trapezoidal in shape;
- the buried layer formed between the well region and a substrate, wherein the buried layer is part of the isolation ring and the substrate is in direct contact with the isolation ring and located below and outside of the isolation ring, while the well region is within the isolation ring;
- a third diode formed between the substrate and the buried layer, wherein an anode of the third diode is connected to the substrate and a cathode of the third diode is connected to the buried layer;
- and
- a first Schottky diode, and wherein an anode of the first Schottky diode is a metal contact connected to a metal contact of the substrate through a suitable semiconductor interconnect device, and a cathode of the first Schottky diode is a region connected to the buried layer.
5 more elements
Dependencies are inferred from the claim text.