Impurity adding apparatus, impurity adding method, and semiconductor element manufacturing method

Patent metadata

Field	Value
Publication number	US-2016284547-A1
Application number	US-201615174468-A
Country	US
Kind code	A1
Filing date	Jun 6, 2016
Priority date	Jun 12, 2014
Publication date	Sep 29, 2016
Grant date	—

Abstract

An impurity-doping apparatus is provided with: a supporting plate which supports a semiconductor substrate; a wall-like block disposed above the supporting plate floating away from the semiconductor substrate, the wall-like block implements a recess inside so as to establish a space for a solution region containing impurity elements, the solution region is localized on an upper surface of the semiconductor substrate, the upper surface being opposite to an bottom surface facing to the supporting plate; and a laser optical system, configured to irradiate a laser beam onto the upper surface of the semiconductor substrate, through the solution region surrounded by the wall-like block, wherein the impurity elements are doped into a part of the semiconductor substrate by irradiation of the laser beam.

First claim

What is claimed is:

1 . An apparatus for doping impurities, comprising:
a supporting plate which supports a semiconductor substrate; a wall-like block disposed above the supporting plate floating away from the semiconductor substrate, the wall-like block implements a recess inside so as to establish a space for a solution region containing impurity elements, the solution region is localized on a surface of the semiconductor substrate on the opposite side of the supporting plate, the wall-like block having a feeding canal and an ejecting canal, the feeding canal being used for injection of the solution and the ejecting canal being used for evacuation of the solution, the feeding and ejecting canals forming a flow path within the recess; and a laser optical system, configured to irradiate a laser beam onto the surface of the semiconductor substrate, through the solution region surrounded by the wall-like block, and configured to move along the flow path on the surface of the semiconductor substrate opposite to the supporting plate, wherein the impurity elements are doped into a part of the semiconductor substrate by irradiation of the laser beam.

2 . The apparatus of claim 1 , wherein the laser optical system irradiates the laser beam in a direction intersecting with the moving direction of the solution.

3 . The apparatus of claim 2 , further comprising an X-Y moving stage which freely moves the supporting plate in X and Y directions which are defined in a plane parallel to the surface of the semiconductor substrate.

4 . The apparatus of claim 3 , wherein the moving direction of the solution along the flow path is the same as the direction that the supporting plate moves in laser doping by irradiation of the laser beam.

5 . The apparatus of claim 4 , wherein the surface of the wall-like block facing the semiconductor substrate is parallel to the surface of the semiconductor substrate, the apparatus further comprising a driving system, configured to move the X-Y moving stage vertically to the X and Y directions so as to control a gap between the surface of the wall-like block facing the semiconductor substrate and the surface of the semiconductor substrate.

6 . The apparatus of claim 5 , wherein the gap is set to such a height that the solution is prevented by surface tension of the solution from leaking out of the wall-like block, and the solution is held between the surface of the wall-like block facing the semiconductor substrate and the surface of the semiconductor substrate.

7 . The apparatus of claim 6 , wherein the height of the gap is not more than 200 μm.

8 . The apparatus of claim 7 , further comprising a circulation system circulating the solution surrounded by the wall-like block, while keeping the solution in contact with the surface of the semiconductor substrate.

9 . The apparatus of claim 8 , the laser beam emitted by the laser optical system has a wavelength having a larger energy than the band-gap energy of the semiconductor substrate.

10 . The apparatus of claim 9 , wherein the surface of the wall-like block facing the semiconductor substrate is water-repellent.

11 . The apparatus of claim 10 , wherein the recess penetrates the wall-like block, further comprising a window member in the recess, which transmits and introduces the laser beam.

12 . A method for doping impurities, comprising:
forming a solution region where solution containing impurity elements is localized, on a surface of a semiconductor substrate; moving the localized solution on the surface of the semiconductor substrate; and irradiating a laser beam to the surface of the semiconductor substrate through the solution region, wherein the impurity elements are doped into a part of the semiconductor substrate.

13 . The method of claim 12 , wherein in the step of irradiating the laser beam, the laser beam is irradiated in a direction intersecting with the moving direction of the solution.

14 . The method of claim 13 , further comprises:
moving the semiconductor substrate in X and Y directions, which are defined in a plane parallel to the surface of the semiconductor substrate, wherein a pattern in which the impurity elements are doped into a part of the semiconductor substrate is directly delineated.

15 . The method of claim 14 , wherein in the step of irradiating the laser beam, the semiconductor substrate is moved in the same direction as the moving direction of the solution.

16 . A method of manufacturing a semiconductor device, comprising:
forming a solution region where solution containing impurity elements of a first conductivity type is localized is formed in a part of a surface of a semiconductor substrate of a first or second conductivity type; moving the localized solution on the surface of the semiconductor substrate; and irradiating a laser beam onto the semiconductor substrate through the solution region to form a first semiconductor region of the first conductivity type in the surface of the semiconductor substrate.

17 . The method of claim 16 , wherein in the step of forming the first semiconductor region, the laser beam is irradiated in the direction intersecting with the moving direction of the solution.

18 . The method of claim 17 , wherein in the step of forming the first semiconductor region, the semiconductor substrate is moved in the same direction as the moving direction of the solution.

19 . The method of claim 18 , wherein at the surface of the semiconductor substrate, a second semiconductor region of the first conductivity type is formed beforehand, and
the first semiconductor region is formed in the second semiconductor region so that the first semiconductor region is doped at higher concentration than that of the second semiconductor region.

20 . The method of claim 19 , further comprises:
forming an ohmic electrode layer in the first semiconductor region.

Assignees

• Fuji Electric Co Ltd

Inventors

• Iguchi Kenichi
• Nakazawa Haruo
• Ogino Masaaki

Classifications

• H10P32/19

  Diffusion sources · CPC title

• H10P72/0402

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title

• H10P34/42

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

• H10P32/172

  being crystalline silicon carbide · CPC title

• H10P32/16 Primary

  between a solid phase and a liquid phase · CPC title