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EP-3690954-B1 - SEMICONDUCTOR DEVICE

EP3690954B1EP 3690954 B1EP3690954 B1EP 3690954B1EP-3690954-B1

Inventors

  • Fischer, Björn

Dates

Publication Date
20260506
Application Date
20190204

Claims (15)

  1. A semiconductor device, comprising: a semiconductor body (100) comprising a first surface (101) and a second surface (102) opposite to the first surface (101) in a vertical direction (y); a first semiconductor region (32, 701) of a first doping type that is electrically coupled to a first terminal (S, A); a second semiconductor region (111, 702) of a second doping type that is electrically coupled to a second terminal (D, K); and a third semiconductor region (35, 703) of the second doping type but less highly doped than the second semiconductor region (111, 702) that extends in an active region (220) of the semiconductor device from the first semiconductor region (32, 701) to the second semiconductor region (111, 702) in the vertical direction (y); a horizontal field-stop-region (39, 704) of the first doping type that extends in an edge region (210) of the semiconductor device from the first semiconductor region (32, 701) into the semiconductor body (100) in the vertical direction (y) such that it directly adjoins the first semiconductor region (32, 701) in the vertical direction (y) and the second semiconductor region (111, 702) in a horizontal direction (x) that is perpendicular to the vertical direction (y); and a horizontal compensation region (80, 706) of the first doping type that extends from the horizontal field-stop-region (39, 704) into the second semiconductor region (111, 702) in the horizontal direction (x).
  2. The semiconductor device of claim 1, wherein the horizontal field-stop-region (39, 704) surrounds the second semiconductor region (111, 702) and the third semiconductor region (35, 703) in a horizontal plane.
  3. The semiconductor device of claim 1 or 2, wherein the second semiconductor region (111, 702) has a first width (w1) in the horizontal direction (x); the horizontal compensation region (80, 706) has a second width (w2) in the horizontal direction (x); and the second width (w2) is smaller than the first width (w1).
  4. The semiconductor device of any of claims 1 to 3, wherein the second semiconductor region (111, 702) has a first thickness (d1) in the vertical direction (y); the horizontal compensation region (80, 706) has a second thickness (d2) in the vertical direction (y); and the second thickness (d2) is smaller than the first thickness (d1).
  5. The semiconductor device of any of claims 1 to 4, wherein a dopant dose of the horizontal compensation region (80, 706) is chosen from a range of 70-130% of a dopant dose of the second semiconductor region (111, 702).
  6. The semiconductor device of any of claims 1 to 5, wherein the horizontal field-stop-region (39, 704) comprises a first section (391, 7041) and a second section (392, 7042), wherein the second section (392, 7042) is arranged adjacent to the horizontal compensation region (80, 706).
  7. The semiconductor device of claim 6, wherein the second semiconductor region (111) is a vertical field-stop-region, and the semiconductor device further comprises a drain region (36) arranged in the active region (220) of the semiconductor device adjacent to the second semiconductor region 111 in the vertical direction (y), a third section (393) of the horizontal field-stop-region (39) and a junction termination extension region (70) located between the drain region (36) and the third section (393) in the horizontal direction (x).
  8. The semiconductor device of claim 7, further comprising a plurality of transistor cells (30) at least partly integrated in the active region (220), each transistor cell (30) comprising a source region (31), a body region (32) formed by a section of the first semiconductor region, a drift region (35) formed by a section of the third semiconductor region and separated from the source region (31) by the body region (32), and a gate electrode (33) dielectrically insulated from the body region (32).
  9. The semiconductor device of claim 8, further comprising vertical compensation regions (38) extending from the body regions (32) towards the second semiconductor region (111, 702).
  10. The semiconductor device of claim 8 or 9, further comprising a source electrode (41) arranged above the first surface (101) and electrically connected to the source regions (31) of the plurality of transistor cells (30).
  11. The semiconductor device of any of claims 7 to 10, further comprising a drain electrode (43) electrically connected to the drain region (36), and a gate pad electrically connected to the gate electrodes (33) of the plurality of transistor cells (30), wherein the drain electrode (43) and the gate pad are arranged above the second surface (102).
  12. The semiconductor device of any of the preceding claims, further comprising an intrinsic semiconductor region (705) arranged between the first semiconductor region 701 and the second semiconductor region (702) in the vertical direction (y), and arranged between the third semiconductor region (703) and the horizontal field-stop-region (704) in the horizontal direction (x).
  13. A method comprising: forming a second semiconductor region (111, 702) in a first layer of semiconductor material (70) by implanting ions of a second doping type; forming a second section (392, 7042) of a horizontal field-stop-region (39, 704) in the first layer of semiconductor material (70) by implanting ions of a first doping type, wherein the second section (392, 7042) of the horizontal field-stop-region (39, 704) adjoins the second semiconductor region (111, 702) in a horizontal direction (x); forming a horizontal compensation region (80, 706) in the second semiconductor region (111, 702), by implanting ions of the first doping type, wherein the horizontal compensation region (80, 706) extends from the second section (392, 7042) of the horizontal field-stop-region (39, 704) into the second semiconductor region (111, 702) in the horizontal direction (x); depositing a second layer of semiconductor material (71) on the first layer of semiconductor material (70); forming a third semiconductor region (35, 703) of the second doping type in the second layer of semiconductor material (71); forming a first semiconductor region (32, 701) of the first doping type in the second layer of semiconductor material (71), wherein the third semiconductor region (35, 703) extends from the first semiconductor region (32, 701) to the second semiconductor region (111, 702) in a vertical direction (y) that is perpendicular to the horizontal direction (x) such that it adjoins both the first semiconductor region (32, 701) and the second semiconductor region (111, 702) ; and forming a first section (391, 7041) of the horizontal field-stop-region (39, 704) of the first doping type, wherein the first section (391, 7041) extends from the first semiconductor region (32, 701) to the second section (392, 7042) in the vertical direction (y) such that it adjoins both the first semiconductor region (32, 701) and the second section (392, 7042).
  14. The method of claim 13, wherein the first layer of semiconductor material (70) either is a region of at least one of the first doping type and the second doping type, or is an intrinsic or undoped layer.
  15. The method of claim 13 or 14, further comprising forming a plurality of transistor cells (30), each transistor cell (30) comprising a source region (31), a body region (32) formed by a section of the first semiconductor region (32, 701), a drift region (35) formed by a section of the third semiconductor region (35, 703) and separated from the source region (31) by the body region (32), and a gate electrode (33) dielectrically insulated from the body region (32).

Description

TECHNICAL FIELD The instant disclosure relates to a semiconductor device, in particular to a semiconductor device with a large lateral blocking voltage. BACKGROUND Semiconductor devices such as insulated gate power transistor devices, e.g., power MOSFETs (Metal Oxide Semiconductor Field-Effect Transistors), are widely used as electronic switches in various types of electronic applications. In the off-state, such semiconductor devices are required to block a reverse voltage in a vertical direction of the semiconductor device. This requires device regions, over which this reverse voltage drops horizontally. However, such device regions often have a resistance that is not low enough to block the entire voltage. Document WO 2018/034250 A1 discloses a reverse-blocking semiconductor device that includes: a front surface and a back surface on the opposite side from the front surface, a first-conductivity-type semiconductor layer having an end face, an MIS transistor structure formed on the front-surface section of the semiconductor layer, a first electrode for forming a Schottky junction with a part of the semiconductor layer on the back surface of the semiconductor layer, and an electric field relaxation region comprising a high-resistance region having resistance higher than the semiconductor layer, or a second-conductivity-type impurity region, the semiconductor layer being formed so as to extend from the front surface to the back surface in a region surrounding the active region in which the MIS transistor structure is formed. Document US 2015/054119 A1 discloses a device structure including a substrate, a first epitaxial layer, a split floating buried layer, a second epitaxial layer, a doped trench, a protected device, a surface junction termination extension (S-JTE) and a scribe street. The device and the S-JTE are designed at the second epitaxial layer and the split floating buried layer at the joint of the first and second epitaxial layers. The doped trench is penetrated through the second epitaxial layer and connected to the split floating buried layer. The substrate, the first and second epitaxial layers feature the same typed doping which is opposite to that of split floating buried layer and doped trench. Document US 2015/041965 A1 discloses a power semiconductor device including a semiconductor body having a first side, a second side opposite the first side and an outer rim. The semiconductor body includes an active region, an edge termination region arranged between the active region and the outer rim, a first doping region in the active region and connected to a first electrode arranged on the first side, a second doping region in the active region and the edge termination region and connected to a second electrode arranged on the second side, a drift region between the first doping region and the second doping region, the drift region including a first portion adjacent to the first side and a second portion arranged between the first portion and the second doping region, and an insulating region arranged in the edge termination region between the second doping region and the first portion of the drift region. It is desirable to provide a robust semiconductor device that provides a large lateral blocking voltage. SUMMARY One example relates to a semiconductor device. The semiconductor device includes a semiconductor body comprising a first surface and a second surface opposite to the first surface in a vertical direction, a first semiconductor region of a first doping type that is electrically coupled to a first terminal, a second semiconductor region of a second doping type that is electrically coupled to a second terminal, and a third semiconductor region of the second doping type but less highly doped than the second semiconductor region that extends in an active region of the semiconductor device from the first semiconductor region to the second semiconductor region in the vertical direction. A horizontal field-stop-region of the first doping type extends in an edge region of the semiconductor device from the first semiconductor region into the semiconductor body in the vertical direction such that it directly adjoins the first semiconductor region in the vertical direction and the second semiconductor region in a horizontal direction that is perpendicular to the vertical direction. A horizontal compensation region of the first doping type extends from the horizontal field-stop-region into the second semiconductor region in the horizontal direction. One example relates to a method. The method includes forming a second semiconductor region in a first layer of semiconductor material by implanting ions of a second doping type, forming a second section of a horizontal field-stop-region in the first layer of semiconductor material by implanting ions of a first doping type, wherein the second section of the horizontal field-stop-region adjoins the second semiconductor region in a horizontal direction,