Method of manufacturing semiconductor devices and semiconductor device containing hydrogen-related donors

Patent metadata

Field	Value
Publication number	US-10128328-B2
Application number	US-201715793530-A
Country	US
Kind code	B2
Filing date	Oct 25, 2017
Priority date	Oct 31, 2016
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

Crystal lattice defects are generated in a horizontal surface portion of a semiconductor substrate and hydrogen-related donors are formed in the surface portion. Information is obtained about a cumulative dopant concentration of dopants, including the hydrogen-related donors, in the surface portion. Based on the information about the cumulative dopant concentration and a dissociation rate of the hydrogen-related donors, a main temperature profile is determined for dissociating a defined portion of the hydrogen-related donors. The semiconductor substrate is subjected to a main heat treatment applying the main temperature profile to obtain, in the surface portion, a final total dopant concentration deviating from a target dopant concentration by not more than 15%.

First claim

What is claimed is:

1. A method of manufacturing a semiconductor device, the method comprising:
generating crystal lattice defects in a horizontal surface portion of a semiconductor substrate;
forming hydrogen-related donors in the surface portion;
obtaining information about a cumulative dopant concentration of dopants including the hydrogen-related donors, in the surface portion;
determining, based on the information about the cumulative dopant concentration, a main temperature profile for dissociating a defined portion of the hydrogen-related donors; and
subjecting the semiconductor substrate to a main heat treatment applying the main temperature profile to obtain, in the surface portion, a final total dopant concentration deviating from a target dopant concentration by not more than 15%.

2. The method of claim 1 , wherein the surface portion contains extrinsic dopants and the cumulative dopant concentration is the sum of an extrinsic net dopant concentration and a preparatory hydrogen-related donor concentration after the forming of the hydrogen-related donors.

3. The method of claim 1 , wherein the semiconductor substrate contains extrinsic donors and an extrinsic net dopant concentration is at least 1E13 cm −3 .

4. The method of claim 1 , wherein the semiconductor substrate contains extrinsic donors and an extrinsic net dopant concentration is at most 5E12 cm −3 .

5. The method of claim 1 , wherein the semiconductor substrate is intrinsic.

6. The method of claim 1 , wherein forming the hydrogen-related donors comprises a preparatory heat treatment for diffusing hydrogen into the surface portion.

7. The method of claim 1 , wherein generating the crystal lattice defects comprises irradiating the semiconductor substrate with protons.

8. The method of claim 7 , further comprising:
after implanting the protons, thinning the semiconductor substrate from a side opposite to the front surface so that a base portion comprising an end-of-range peak of the proton implant is removed.

9. The method of claim 7 , wherein forming the hydrogen-related donors comprises a preparatory heat treatment for diffusing the implanted protons into the surface portion.

10. The method of claim 9 , wherein a maximum temperature applied in the preparatory heat treatment is above 470° C. and at most 510° C.

11. The method of claim 1 , wherein a maximum temperature applied in the main heat treatment is above 510° C.

12. The method of claim 1 , wherein at least 50% of a total duration of the main temperature profile is an isothermal process given by a constant main process temperature and a main process time for which the constant main process temperature is applied.

13. The method of claim 1 , further comprising:
forming anode/body wells in the semiconductor substrate,
wherein the anode/body wells form first pn junctions with cathode/drain structures,
wherein the cathode/drain structures comprise drift zones in the surface portion,
wherein a dopant concentration in the drift zones is equal to the final total dopant concentration.

14. The method of claim 1 , wherein the information about the cumulative dopant concentration comprises a capacitive/voltage measurement across at least one of a pn junction and a Schottky contact formed by the surface portion.

15. The method of claim 14 , wherein a contact probe is pressed against a section of the front surface exposing the surface portion.

16. The method of claim 1 , further comprising:
forming an interlayer dielectric at a front side of the semiconductor substrate before subjecting the semiconductor substrate to the main heat treatment.

17. The method of claim 1 , further comprising:
forming a plurality of separated semiconductor dies from the semiconductor substrate after subjecting the semiconductor substrate to the main heat treatment.

18. The method of claim 1 , wherein at least 25% of donors in the semiconductor substrate are hydrogen-related donors after the main heat treatment.

19. The method of claim 1 , wherein an intrinsic oxygen concentration in the semiconductor substrate is in a range from 1E17 cm −3 to 6E17 cm −3 .

20. The method of claim 1 , wherein a substitutional carbon concentration in the semiconductor substrate is in a range from 1E14 cm −3 to 5E15 cm −3 .

21. The method of claim 1 , further comprising:
after the main heat treatment, implanting protons to form a field stop layer in the semiconductor substrate.

22. The method of claim 21 , further comprising:
subjecting the semiconductor substrate to a supplementary heat treatment which activates the protons to form the field stop layer,
wherein a maximum temperature applied in the supplementary heat treatment is below 420° C.

23. The method of claim 1 , wherein the semiconductor substrate is subjected to the main heat treatment before forming a first metallization at a front side.

Assignees

• Infineon Technologies Ag

Inventors

• Jelinek Moriz
• Weber Hans
• Schulze Hans-Joachim
• Laven Johannes Georg
• Schustereder Werner

Classifications

• H10P95/902

  for the formation of PN junctions without addition of impurities · CPC title

• H10P95/94

  Hydrogenation or deuterisation, e.g. using atomic hydrogen from a plasma · 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

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title