Method for forming trench semiconductor device having schottky barrier structure

Patent metadata

Field	Value
Publication number	US-2020105877-A1
Application number	US-201916701933-A
Country	US
Kind code	A1
Filing date	Dec 3, 2019
Priority date	Aug 2, 2018
Publication date	Apr 2, 2020
Grant date	—

Abstract

A method for forming a semiconductor device includes providing a region of semiconductor material. The method includes providing a trench structure having a trench extending into the region of semiconductor material from a first major surface, and a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region. The method includes providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure. In one example, providing the Schottky contact region comprises forming a layer of material comprising as-formed nickel-chrome; exposing the layer of material to a temperature in a range from about 400 degrees Celsius through about 550 degrees Celsius; and after the step of exposing, removing any unreacted portions of the layer of material.

First claim

What is claimed is:

1 . A method of forming a semiconductor device, comprising:
providing a region of semiconductor material comprising a first major surface and a second major surface opposite to the first major surface; providing a trench structure comprising:
a trench extending into the region of semiconductor material from the first major surface; and
a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region;
providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure, wherein providing the Schottky contact region comprises:
forming a layer of material disposed adjacent to the first major surface, the layer of material comprising an as-formed layer of nickel-chrome and having a first thickness;
exposing the layer of material to a temperature in a range from about 400 degrees Celsius through about 550 degrees Celsius; and
after the step of exposing, removing any unreacted portions of the layer of material.

2 . The method of claim 1 , wherein:
forming the layer of material comprises forming the layer of material consisting essentially of nickel-chrome.

3 . The method of claim 1 , wherein:
forming the layer of material comprises forming the layer of material consisting of nickel-chrome.

4 . The method of claim 1 , wherein:
forming the layer of material comprises forming the layer of material comprising a 40% nickel-60% chrome alloy material.

5 . The method of claim 1 , wherein:
forming the layer of material comprises providing the first thickness in a range from about 400 Angstroms through about 1300 Angstroms.

6 . The method of claim 1 , wherein:
forming the layer of material comprises providing the first thickness in a range from about 500 Angstroms through about 1100 Angstroms.

7 . The method of claim 1 , wherein:
forming the layer of material comprises providing the first thickness in a range from about 600 Angstroms through about 1000 Angstroms.

8 . The method of claim 1 , further comprising:
forming a conductive layer overlying the Schottky contact region.

9 . The method of claim 1 , wherein:
providing the trench structure comprises providing an active trench structure.

10 . The method of claim 1 , wherein:
exposing the layer of material to the temperature comprises exposing to a temperature in a range from about 400 degrees Celsius to about 500 degrees Celsius.

11 . The method of claim 10 , wherein:
exposing the layer of material to the temperature comprises exposing for a time. period from about 70 seconds to about 100 seconds.

12 . A method of forming a semiconductor device, comprising:
providing a region of semiconductor material comprising a first major surface and a second major surface opposite to the first major surface; providing a trench structure comprising:
a trench extending into the region of semiconductor material from the first major surface; and
a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region, wherein the dielectric region is disposed along opposing sidewall surfaces of the trench and disposed along a lower surface of the trench; and the dielectric region comprises a first uppermost surface.
providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure, wherein providing the Schottky contact region comprises:
forming a first layer of material disposed adjacent to the first major surface, the first layer of material consisting essentially of nickel-chrome and having a first thickness;
exposing the first layer of material to a temperature in a range from about 400 degrees Celsius through about 550 degrees Celsius; and
after the step of exposing, removing any unreacted portions of the first layer of material

13 . The method of claim 12 , wherein:
forming the layer of material comprises forming the layer of material comprising a 40% nickel-60% chrome alloy material.

14 . The method of claim 12 , wherein:
forming the layer of material comprises providing the first thickness in a range from about 400 Angstroms through about 1300 Angstroms.

15 . The method of claim 12 , wherein:
providing the trench structure comprises providing the first uppermost surface of the dielectric region extending above an upper surface of the Schottky region in a cross-sectional view.

16 . The method of claim 12 , further comprising:
forming a conductive layer overlying the Schottky contact region, wherein: providing the trench structure comprises providing an active trench structure; and exposing the layer of material comprises exposing for a time period of about 70 seconds to about 100 seconds.

17 . The method of claim 12 , wherein:
providing the region of semiconductor material comprises:
providing a semiconductor substrate; and
providing a semiconductor layer overlying the substrate;
the semiconductor layer includes the first major surface; and the semiconductor layer comprises a non-uniform dopant profile over its thickness.

18 . A method of forming a semiconductor device, comprising:
providing a region of semiconductor material comprising a first major surface and a second major surface opposite to the first major surface; providing a trench structure comprising:
a trench extending into the region of semiconductor material from the first major surface; and
a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region, wherein:
the dielectric region is disposed along opposing sidewall surfaces of the trench and disposed along a lower surface of the trench; and
the dielectric region comprises a first uppermost surface; and

providing a Schottky contact region disposed adjacent to the first major surface and adjacent to the trench structure, wherein providing the Schottky contact region comprises:
forming a conductive structure, the conductive structure being one of:
a layer of material consisting essentially of nickel-chrome disposed adjacent to the first major surface; or
a first layer of material consisting essentially of titanium disposed adjacent to the first major surface and a second layer of material disposed adjacent to the first layer of material and consisting essentially of nickel-platinum;

exposing the conductive structure to an elevated temperature to form a silicide structure; and
after the step of exposing, removing any unreacted portions of the conductive structure.

19 . The method of claim 18 , wherein:
forming the conductive structure comprises:
forming the first layer of material consisting essentially of titanium and having a first thickness; and
forming the second layer of material consisting essentially of nickel-platinum and having a second thickness;
exposing comprises exposing the first layer of material and the second layer of material to a temperature in a range from about 650 degrees Celsius through about 700 degrees Celsius; and forming the conductive structure comprises providing a first thickness to second thickness ratio greater than or equal to 1.33:1.

20 . The method of claim 18 , wherein:
forming the conductive structure comprises:
forming the layer of material consisting essentially of nickel-chrome and having a thickness in a range from about 500 Angstroms through about 1100 Angstroms;
exposing comprises expo

Assignees

• Semiconductor Components Ind Llc

Inventors

• Thomason Michael
• Quddus Mohammed T
• Mudholkar Mihir

Classifications

• H10D64/0122

  to diamond, semiconducting diamond-like carbon or graphene · CPC title

• H10D64/0121 Primary

  to Group IV semiconductors · CPC title

• H01L21/0435

  Electricity · mapped topic

• H01L29/872

  Electricity · mapped topic

• H01L21/28537

  Electricity · mapped topic