Method for producing a superjunction device

Patent metadata

Field	Value
Publication number	US-11342187-B2
Application number	US-202016850309-A
Country	US
Kind code	B2
Filing date	Apr 16, 2020
Priority date	Jul 14, 2016
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

Forming a semiconductor arrangement includes providing a first semiconductor layer having a first surface, forming a first plurality of trenches in the first surface of the first semiconductor layer, each of the trenches in the first plurality having first and second sidewalls that extend from the first surface to a bottom of the respective trench, implanting first type dopant atoms into the first and second sidewalls of each of the trenches in the first plurality, implanting second type dopant atoms into the first and second sidewalls of each of the trenches in the first plurality, and annealing the semiconductor arrangement to simultaneously activate the first type dopant atoms and the second type dopant atoms.

First claim

What is claimed is:

1. A method of forming a semiconductor arrangement, the method comprising:
providing a first semiconductor layer comprising a first surface;
forming a first plurality of trenches in the first surface of the first semiconductor layer, each of the trenches in the first plurality comprising first and second sidewalls that extend from the first surface to a bottom of the respective trench;
implanting first type dopant atoms into the first and second sidewalls of each of the trenches in the first plurality;
implanting second type dopant atoms into the first and second sidewalls of each of the trenches in the first plurality; and
annealing the semiconductor arrangement to simultaneously activate the first type dopant atoms and the second type dopant atoms
wherein the annealing of the semiconductor arrangement forms adjoining first conductivity type regions and second conductivity type regions,
wherein the first type dopant atoms have a different diffusion constant as the second type dopant atoms such that the implanted first type dopant atoms laterally diffuse away from the first and second sidewalls of each of the trenches in the first plurality at a different speed as the implanted second type dopant atoms during the annealing of the semiconductor arrangement,
forming a second semiconductor layer in the first plurality of trenches and on mesa regions between the first plurality of the trenches of the first semiconductor layer;
wherein the second semiconductor layer is formed before the annealing of the semiconductor arrangement, and
wherein the annealing of the semiconductor arrangement causes the implanted first type dopant atoms and the implanted second type dopant atoms to laterally diffuse from the first semiconductor layer into the second semiconductor layer.

2. The method of claim 1 , further comprising:
forming a second plurality of trenches in a first surface of the second semiconductor layer, each of the trenches in the second plurality comprising first and second sidewalls that extend from the first surface of the second semiconductor layer to a bottom of the respective trench;
implanting first type dopant atoms into the first and second sidewalls of each of the trenches in the second plurality; and
implanting second type dopant atoms into the first and second sidewalls of each of the trenches in the second plurality,
wherein the annealing of the semiconductor arrangement simultaneously activates the first type dopant atoms and the second type dopant atoms implanted into the first semiconductor layer and the second semiconductor layer.

3. The method of claim 1 , wherein before the annealing of the semiconductor arrangement the second semiconductor layer has a basic dopant concentration that is lower than a net doping concentration of the first conductivity type regions and second conductivity type regions.

4. The method of claim 1 , wherein the diffusion constant of one of the first type dopant atoms and the second type dopant atoms is at least 1.5 times or at least 2 times the diffusion constant of the other one of the first type dopant atoms and the second type dopant atoms.

5. The method of claim 1 , wherein the diffusion constant of the first type dopant atoms is less than the diffusion constant of the second type dopant atoms such that the first conductivity type regions form closer to the first and second sidewalls of each of the trenches in the first plurality than the second conductivity type regions.

6. The method of claim 1 wherein the first type dopant atoms and the second type dopant atoms are simultaneously implanted into the first sidewalls of each of the trenches in the first plurality by a first common implantation process, and wherein the first type dopant atoms and the second type dopant atoms are simultaneously implanted into the second sidewalls of each of the trenches in the first plurality by a second common implantation process.

7. A method of forming a semiconductor arrangement, the method comprising:
providing a first semiconductor layer;
forming a first plurality of trenches in the first semiconductor layer;
implanting first type dopant atoms and second type dopant atoms into sidewalls of the trenches of the first plurality;
forming a second semiconductor layer in the first plurality of trenches and on mesa regions between the first plurality of the trenches of the first semiconductor layer;
forming a second plurality of trenches in the second semiconductor layer;
implanting first type dopant atoms and second type dopant atoms into sidewalls of the trenches of the second plurality; and
annealing the semiconductor arrangement to simultaneously activate the first type dopant atoms and the second type dopant atoms implanted into the first semiconductor layer and the second semiconductor layer.

8. The method of claim 7 , wherein the first type dopant atoms implanted into the first semiconductor layer have a different diffusion constant as the second type dopant atoms implanted into the first semiconductor layer, and wherein the first type dopant atoms implanted into the second semiconductor layer have a different diffusion constant as the second type dopant atoms implanted into the second semiconductor layer.

Assignees

• Infineon Technologies Austria Ag

Inventors

• Mauder Anton
• Weber Hans
• Hirler Franz
• Laven Johannes Georg
• Schulze Hans-Joachim
• Schustereder Werner
• Treiber Maximilian
• Tutuc Daniel
• Voerckel Andreas

Classifications

• H10P30/222 Primary

  characterised by the angle between the ion beam and the crystal planes or the main crystal surface (characterised by the angle between the ion beam and the mask H10P30/221) · CPC title

• H10P95/906

  for altering the shape of semiconductors, e.g. smoothing the surface · CPC title

• H10D62/058

  by using trenches, e.g. implanting into sidewalls of trenches or refilling trenches · CPC title

• H10D62/111

  Multiple RESURF structures, e.g. double RESURF or 3D-RESURF structures · CPC title

• H10D62/157

  Impurity concentrations or distributions · CPC title