Method for postdoping a semiconductor wafer

Patent metadata

Field	Value
Publication number	US-9559020-B2
Application number	US-201514963855-A
Country	US
Kind code	B2
Filing date	Dec 9, 2015
Priority date	Aug 14, 2013
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A method for treating a semiconductor wafer having a basic doping is disclosed. The method includes determining a doping concentration of the basic doping, and adapting the basic doping of the semiconductor wafer by postdoping. The postdoping includes at least one of the following methods: a proton implantation and a subsequent thermal process for producing hydrogen induced donors. In this case, at least one of the following parameters is dependent on the determined doping concentration of the basic doping: an implantation dose of the proton implantation, and a temperature of the thermal process.

First claim

The invention claimed is:

1. A method for treating a semiconductor wafer having a basic doping, comprising:
determining a doping concentration of the basic doping; and
adapting the basic doping of the semiconductor wafer by postdoping the semiconductor wafer comprising a proton implantation and a subsequent thermal process for producing hydrogen induced donors,
wherein at least one of the following parameters is dependent on the determined doping concentration of the basic doping:
an implantation dose of the proton implantation, and
a temperature of the thermal process.

2. The method as claimed in claim 1 , wherein the temperature during the thermal process is between 400° C. and 570° C. or between 450° C. and 550° C.

3. The method as claimed in claim 2 , wherein the duration of the thermal process is between one hour and ten hours or between three hours and six hours.

4. The method as claimed in claim 1 ,
wherein the semiconductor wafer has a first side associated with a subsequent fabrication of a completed semiconductor device thereon, and
wherein the proton implantation is carried out via the first side.

5. The method as claimed in claim 4 , wherein the proton implantation comprises at least two proton implantation acts in which protons are implanted with different implantation energies.

6. The method as claimed in claim 1 ,
wherein the semiconductor wafer has a first side associated with a subsequent fabrication of a completed semiconductor device thereon, and a second side opposite the first side, and
wherein the proton implantation is carried out via the second side.

7. The method as claimed in claim 1 , wherein determining the doping concentration of the basic doping of the semiconductor wafer comprises a measurement of a resistivity of the semiconductor wafer.

8. The method as claimed in claim 7 ,
wherein the semiconductor wafer is a semiconductor wafer obtained by dividing a cylindrical single crystal, and
wherein the resistivity is measured after the single crystal has been divided.

9. The method as claimed in claim 7 ,
wherein the semiconductor wafer is a semiconductor wafer obtained by dividing a cylindrical single crystal, and
wherein the resistivity is measured before the single crystal is divided.

10. The method as claimed in claim 1 , wherein the basic doping is an n-type basic doping.

11. The method as claimed in claim 10 , wherein the basic doping is formed by phosphorus atoms.

12. The method as claimed in claim 1 , wherein the basic doping is a p-type basic doping.

13. The method as claimed in claim 1 , wherein the doping concentration of the basic doping is higher than 1E13 cm −3 .

14. The method as claimed in claim 13 , wherein the doping concentration of the basic doping is higher than 1E12 cm −3 .

15. The method as claimed in claim 1 , wherein a doping concentration of the basic doping before the adaptation is between 20% to 60% of a doping concentration after the adaptation.

16. The method as claimed in claim 1 ,
wherein protons are implanted during the proton implantation via a first side of the semiconductor wafer into an end-of-range region of the semiconductor wafer, and
wherein the thermal process is chosen such that a doping concentration added by the adaptation is approximately homogeneous in at least between 60% to at least 80% of a volume of the semiconductor wafer in a region between the end-of-range region and the first side.

17. The method as claimed in claim 16 , wherein a ratio between a maximum doping concentration and a minimum doping concentration in the at least approximately homogeneously doped volume is less than 1.2.

18. The method as claimed in claim 1 ,
wherein protons are implanted during the proton implantation via a first side of the semiconductor wafer into an end-of-range region, and
wherein a portion of the semiconductor wafer is removed at least as far as the end-of-range region proceeding from a second side situated opposite the first side.

19. The method as claimed in claim 18 , wherein the first side of the semiconductor wafer is associated with a subsequent fabrication of a completed semiconductor device thereon.

20. The method as claimed in claim 1 , wherein a device to be manufactured on the semiconductor wafer comprises a device requiring a high dielectric strength, and wherein the resultant adapted basic doping in the semiconductor wafer results in a region that comprises a drift region of a MOSFET type device or a base region for a diode or thyristor device.

Assignees

• Infineon Technologies Ag

Inventors

• Ploss Reinhard
• Oefner Helmut
• Schulze Hans-Joachim

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P74/207

  Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics · CPC title

• H10P34/40

  with high-energy radiation · CPC title

• H10P34/20

  for inducing a nuclear reaction transmuting chemical elements · CPC title