Method of manufacturing a superjunction semiconductor device

Patent metadata

Field	Value
Publication number	US-11329126-B2
Application number	US-201816018412-A
Country	US
Kind code	B2
Filing date	Jun 26, 2018
Priority date	Jun 27, 2017
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

In an embodiment, a method of fabricating a superjunction semiconductor device includes implanting first ions into a first region of a first epitaxial layer using a first implanting apparatus and nominal implant conditions to produce a first region in the first epitaxial layer comprising the first ions and a first implant characteristic and implanting second ions into a second region of the first epitaxial layer, the second region being laterally spaced apart from the first region, using second nominal implanting conditions estimated to produce a second region in the first epitaxial layer having the second ions and a second implant characteristic that lies within an acceptable maximum difference of the first implant characteristic.

First claim

What is claimed is:

1. A method of fabricating a superjunction semiconductor device, the method comprising:
for a first implanting apparatus, selecting nominal implant conditions for implanting ions into a region of a first epitaxial layer of a superjunction semiconductor device formed on a substrate such that the region has a nominal implant characteristic, wherein the first implanting apparatus comprises an intrinsic apparatus implant characteristic that is applied to the nominal implant conditions when implanting the ions using the first implanting apparatus;
determining an acceptable maximum difference between a first implant characteristic of a first region of the first epitaxial layer comprising first ions for forming a first compensation column of the superjunction semiconductor device, the first compensation column comprising a first conductivity type, and a second implant characteristic of a second region of the first epitaxial layer comprising second ions for forming a second compensation column of the superjunction semiconductor device, the second compensation column comprising a second conductivity type opposing the first conductivity type;
implanting the first ions into the first region of the first epitaxial layer using the first implanting apparatus and the nominal implant conditions to produce the first region in the first epitaxial layer comprising the first ions and the first implant characteristic; and
implanting the second ions into the second region of the first epitaxial layer, the second region being laterally spaced apart from the first region, using second nominal implanting conditions estimated to produce the second region in the first epitaxial layer having the second ions and the second implant characteristic that lies within the acceptable maximum difference.

2. The method of claim 1 , wherein the intrinsic apparatus implant characteristic causes a variation from the nominal implant characteristic in the first implant characteristic in the first region.

3. The method of claim 1 , wherein the second ions are implanted into the second region using the first implanting apparatus.

4. The method of claim 1 , wherein the intrinsic apparatus implant characteristic further comprises a time dependent component and the second ions are implanted into the second region using the first apparatus within a pre-determined time period from the implanting of the first ions, wherein the pre-determined time period is estimated to produce the second implant characteristic that lies within the acceptable maximum difference after applying the intrinsic apparatus implant characteristic comprising the time dependent component to the nominal implant conditions.

5. The method of claim 1 , wherein the first implant characteristic comprises a dose D and the acceptable maximum difference is the dose D±1%.

6. The method of claim 1 , wherein the implanting the first ions in the first region of the first epitaxial layer is carried out two times at different acceleration energy levels, and/or wherein the implanting the second ions in the second region of the first epitaxial layer is carried out two times at different acceleration energy levels.

7. The method of claim 1 , further comprising:
applying a first photosensitive polymer to the epitaxial layer;
forming a first opening in the first photosensitive polymer layer;
implanting the first ions into the first opening to form the first region;
removing the first photosensitive polymer layer;
applying a second photosensitive layer to the epitaxial layer;
forming a second opening in the second photosensitive polymer layer, the second opening being positioned laterally adjacent and spaced apart from the first region comprising the first ions, the first region being covered by the second photosensitive polymer layer; and
implanting the second ions into the second opening to form the second region.

8. The method of claim 7 , wherein the first opening has a nominal width w 1 and the second opening has a nominal width w 2 , wherein w 1 =w 2 .

9. The method of claim 7 , wherein the first photosensitive polymer layer comprises a first photosensitive polymer composition and the second photosensitive polymer layer comprises the first photosensitive polymer composition.

10. The method of claim 7 , wherein the first photosensitive polymer layer is cured using first curing conditions and the second photosensitive polymer layer is cured using the first curing conditions.

11. The method of claim 7 , wherein the first photosensitive polymer layer comprises a nominal thickness t 1 and the second photosensitive polymer layer comprises a nominal thickness t 2 , wherein t 1 =t 2 .

12. The method of claim 7 , wherein the first photosensitive polymer layer is applied using first lithographic apparatus and the second photosensitive polymer layer is applied using the first lithographic apparatus.

13. The method of claim 7 , further comprising:
determining the size of the first opening in the first photosensitive polymer layer;
determining a difference between the measured size of the first opening and the desired nominal size of the first opening; and
if the difference is greater than a predetermined limit, adjusting the size of the first opening.

14. The method of claim 7 , further comprising:
determining the size of the first opening in the first photosensitive polymer layer;
determining a difference between the measured size of the first opening and the desired nominal size of the first opening; and
if the difference is greater than a predetermined limit, adjusting a dose of the first ions implanted through the first opening so that the dose of the first ions in the first region lies within a tolerance range of the first implant characteristic in the first region.

15. The method of claim 7 , further comprising:
determining the size of the first opening in the first photosensitive polymer layer;
determining a difference between the measured size of the first opening and the desired nominal size of the first opening; and
if the difference is greater than a predetermined limit, adjusting the exposure conditions applied to the second photosensitive polymer layer applied to the epitaxial layer to form the second opening.

16. The method of claim 7 , further comprising:
determining a size of the first opening in the first photosensitive polymer layer,
determining a difference between the measured size of the first opening and the desired nominal size of the first opening; and
if the difference is greater than a predetermined limit, adjusting a dose of the second ions implanted through the second opening so that the dose of the second ions in the second region lies within a tolerance range of the dose of the first ions in the first region.

17. The method of claim 1 , further comprising:
depositing a second epitaxial layer on the first epitaxial layer comprising the first region having the first ions and the second region having the second ions;
implanting first ions into a third region of the second epitaxial semiconductor layer, the third region being arranged above the first region, wherein the first ions are implanted into the third region using a second implanting apparatus and third nominal implant conditions to produce the third region comprising the first ions and a third implant characteristic, wherein the second implanting apparatus comprises a second intrinsic apparatus characteristic that is applied to the third nominal implant conditions when implanting the first ions using the second implanting apparatus and the third nom

Assignees

• Infineon Technologies Austria Ag

Inventors

• Tilke Armin
• Weber Hans
• Fachmann Christian
• Knoefler Roman
• Mezoesi Gabor
• Pippan Manfred
• Rupp Thomas
• Treu Michael
• Willmeroth Armin

Classifications

• H10P30/40

  into insulating materials · CPC title

• H10W20/081

  by forming openings in the dielectric parts · CPC title

• H10P30/204

  into Group IV semiconductors · CPC title

• H10D62/051

  Forming charge compensation regions, e.g. superjunctions · CPC title

• H10D62/111 Primary

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