Impurity introducing method, impurity introducing apparatus, and method of manufacturing semiconductor element

Patent metadata

Field	Value
Publication number	US-2016005606-A1
Application number	US-201514729491-A
Country	US
Kind code	A1
Filing date	Jun 3, 2015
Priority date	Jul 4, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

A method for introducing impurity into a semiconductor substrate includes bringing a solution containing a compound of an impurity element into contact with a primary surface of a semiconductor substrate; and irradiating the primary surface of the semiconductor substrate with a laser beam through the solution to raise a temperature of the primary surface of the semiconductor substrate at a position irradiated by the laser beam so as to dope the impurity element into the semiconductor substrate. The laser beam irradiation is performed such that the raised temperature does not return to room temperature until a prescribed dose of the impurity element is caused to be doped into the semiconductor substrate.

First claim

What is claimed is:

1 . A method for introducing impurity into a semiconductor substrate, comprising:
bringing a solution containing a compound of an impurity element into contact with a primary surface of a semiconductor substrate; and irradiating the primary surface of said semiconductor substrate with a laser beam through the solution to raise a temperature of the primary surface of said semiconductor substrate at a position irradiated by the laser beam so as to dope the impurity element into the semiconductor substrate, wherein said laser beam irradiation is performed such that said raised temperature does not return to room temperature until a prescribed dose of the impurity element is caused to be doped into the semiconductor substrate.

2 . The method according to claim 1 , wherein said laser beam is a continuous wave.

3 . The method according to claim 1 , wherein a waveform of said laser beam is a continuous waveform formed by a plurality of pulse waves joining together.

4 . The method according to claim 2 , wherein irradiating the semiconductor substrate with the laser beam includes:
moving said semiconductor substrate in an X-Y direction defined within a plane parallel to the primary surface of said semiconductor substrate during the laser irradiation so as to directly define a pattern on the primary surface of the semiconductor substrate in which said impurity element is introduced to said semiconductor substrate.

5 . The method according to claim 4 , wherein irradiating the semiconductor substrate with the laser beam includes:
providing an optical fiber with one end face disposed within said solution, and irradiating the primary surface of said semiconductor substrate with the laser beam that is emitted from said one end face of the optical fiber.

6 . The method according to claim 3 , wherein irradiating the semiconductor substrate with the laser beam includes:
moving said semiconductor substrate in an X-Y direction defined within a plane parallel to the primary surface of said semiconductor substrate during the laser irradiation so as to directly define a pattern on the primary surface of the semiconductor substrate in which said impurity element is introduced to said semiconductor substrate.

7 . The method according to claim 6 , wherein irradiating the semiconductor substrate with the laser beam includes:
providing an optical fiber with one end face disposed within said solution, and irradiating the primary surface of said semiconductor substrate with the laser beam that is emitted from said one end face of the optical fiber.

8 . The method according to claim 1 ,
wherein the impurity element in the solution is a first conductivity type, and wherein the primary surface of the semiconductor substrate into which the impurity element is doped is one of the first conductivity type or a second conductivity type so that the laser beam irradiation of the semiconductor substrate with the laser beam forms a first semiconductor region of the first conductivity type in the primary surface of said semiconductor substrate.

9 . The method according to claim 8 , further comprising:
forming a second semiconductor region of the second conductivity type in a surface of said first semiconductor region of said first conductivity type in the primary surface of said semiconductor substrate by bringing said semiconductor substrate into contact with a solution containing a compound of a second conductivity type impurity element and by irradiating said semiconductor substrate with a laser beam, said laser beam irradiation being performed such that a temperature of the semiconductor substrate raised by the laser beam at a position irradiated by the laser beam does not return to room temperature until a prescribed dose of the second conductivity type impurity element is caused to be doped into the semiconductor substrate.

10 . The method according to claim 9 , further comprising:
forming a contact region of the first conductivity type having an impurity concentration greater than that of said first semiconductor region of the first conductivity type in the first semiconductor region by bringing said semiconductor substrate into contact with a solution containing a compound of a first conductivity type impurity element and by irradiating said semiconductor substrate with a laser beam, said laser beam irradiation being performed such that a temperature of the semiconductor substrate raised by the laser beam at a position irradiated by the laser beam does not return to room temperature until a prescribed dose of the first conductivity type impurity element is caused to be doped into the semiconductor substrate.

11 . The method according to claim 10 , further comprising:
forming an ohmic electrode layer on said contact region.

12 . The method according to claim 8 , further comprising:
forming a second semiconductor region of the first conductive type having an impurity concentration greater than that of said first semiconductor region of the first conductivity type in the first semiconductor region by bringing said semiconductor substrate into contact with a solution containing a compound of a first conductivity type impurity element and by irradiating said semiconductor substrate with a laser beam, said laser beam irradiation being performed such that a temperature of the semiconductor substrate raised by the laser beam at a position irradiated by the laser beam does not return to room temperature until a prescribed dose of the first conductivity type impurity element is caused to be doped into the semiconductor substrate.

13 . An impurity introducing apparatus, comprising:
a solution vessel configured to store therein a solution containing a compound of an impurity element and configured to hold a semiconductor substrate upon a bottom surface thereof; a support platform that supports the solution vessel; and a laser optical system, including an optical fiber having one end face configured to be disposed within said solution adjacent to a primary surface of the semiconductor substrate so as to raise a temperature of the primary surface of said semiconductor substrate by inputting a laser beam into the optical fiber and irradiating said semiconductor substrate with the laser beam emerging from said one end face of the optical fiber through the solution located between said one end face and said semiconductor substrate, thereby doping the impurity element into the semiconductor substrate.

14 . The impurity introducing apparatus according to claim 13 , wherein said laser optical system includes a laser light source that emits a continuous-wave laser beam.

15 . The impurity introducing apparatus according to claim 13 , wherein said laser optical system includes a laser light source that outputs a pulse beam or pulse beams that irradiate said semiconductor substrate such that said raised temperature does not return to room temperature until a prescribed dose of the impurity element is doped into the semiconductor substrate.

16 . The impurity introducing apparatus according to claim 14 , further comprising:
an X-Y movement stage that freely moves said support platform in an X-Y direction defined within a plane parallel to the primary surface of said semiconductor substrate.

17 . The impurity introducing apparatus according to claim 16 , further comprising:
a Z movement stage that moves said support platform in a Z direction that is perpendicular to said X-Y direction so as to control a height between said one end face of the optical fiber and a top s

Assignees

• Fuji Electric Co Ltd

Inventors

• Nakazawa Haruo
• Iguchi Kenichi
• Ogino Masaaki

Classifications

• H10P34/42

  with electromagnetic radiation, e.g. laser annealing (laser cutting H10P54/20) · CPC title

• H10P32/172 Primary

  being crystalline silicon carbide · CPC title

• H10D30/66

  Vertical DMOS [VDMOS] FETs · CPC title

• H10D30/0291

  of vertical DMOS [VDMOS] FETs · CPC title

• H01L21/268

  Electricity · mapped topic