Hydrogen-doped polycrystalline group IV-based TFT having a larger number of monohydride-IV bonds than higher order-IV bonds

• US 6,335,266 B1
• Filed: 05/15/2000
• Issued: 01/01/2002
• Est. Priority Date: 09/04/1997
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Fujitsu Limited
• Inventors: Kitahara, Kuninori, Murakami, Satoshi, Hara, Akito
• Primary Examiner(s): Bowers, Charles
• Assistant Examiner(s): LEE, HSIEN MING
• Application Number:
  US09/570,684
• Time in Patent Office: 596 Days
• Field of Search: 438/475, 438/483, 438/488, 438/602, 257/65, 257/66
• US Class Current: 438/475
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02595 polycrystalline
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/02691 Scanning of a beam
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: H01L 29/78675 with normal-type structure, e.g. with top gate
• CPC Class Codes: H01L 29/78684 having a semiconductor body comprising semiconductor materials of Group IV not being silicon, or alloys including an element of the group IV, e.g. Ge, SiN alloys, SiC alloys H01L29/7869 takes precedence

Abstract

A polycrystalline semiconductor material containing Si, Ge or SiGe, wherein the material contains H atoms and the number of monohydride structures of couplings between Si or Ge, and H is larger than the number of higher-order hydride structures, or in other words, a peak intensity of a monohydride structure in a local vibration mode measured by a Raman spectral analysis is higher than a peak intensity of a higher-order hydride structure. By configuring the compositions of a polycrystalline semiconductor material in the above manner, the carrier mobility can be made high.

Claims

1. A method of forming a polycrystalline semiconductor layer, comprising the steps of:

forming a polycrystalline semiconductor layer essentially comprising Si, Ge or SiGe, on a support substrate;

adding hydrogen to the polycrystalline semiconductor layer; and

dissociating hydrogen in the polycrystalline semiconductor layer added with hydrogen by heating the polycrystalline semiconductor layer so that the number of monohydride structures of couplings between Si or Ge, and H is larger than the number of higher-order hydride structures.

2. A method of forming a polycrystalline semiconductor layer according to claim 1, wherein said hydrogen dissociating step performs a heat treatment at a temperature of 250°

C. to 500°

C. of the polycrystalline semiconductor layer.

3. A method of forming a polycrystalline semiconductor layer according to claim 1, wherein said hydrogen dissociating step heats the polycrystalline semiconductor layer in a hydrogen atmosphere.

4. A method of forming a polycrystalline semiconductor layer according to claim 1, wherein said hydrogen dissociating step heats the polycrystalline semiconductor layer in an atmosphere containing oxygen or water content.

5. A method of forming a polycrystalline semiconductor layer, comprising the steps of:

forming a polycrystalline semiconductor layer essentially comprising Si, Ge or SiGe, on a support substrate;

adding hydrogen to the polycrystalline semiconductor layer; and

dissociating hydrogen of some hydride structures by heating the polycrystalline semiconductor layer added with hydrogen.

6. A method of forming a polycrystalline semiconductor layer according to claim 5, wherein said hydrogen dissociating step performs a heat treatment at a temperature of 250°

C. to 500°

C. of the polycrystalline semiconductor layer.

7. A method of forming a polycrystalline semiconductor layer according to claim 5, wherein said hydrogen dissociating step heats the polycrystalline semiconductor layer in a hydrogen atmosphere.

8. A method of forming a polycrystalline semiconductor layer according to claim 5, wherein said hydrogen dissociating step heats the polycrystalline semiconductor layer in an atmosphere containing oxygen or water content.

9. A method of evaluating a semiconductor device comprising the steps of:

irradiating a laser beam to a channel region of a thin film transistor formed on the surface of a transparent substrate, the channel region essentially comprising Si, Ge or SiGe; and

comparing a peak intensity of a monohydride structure of couplings between Si or Ge, and H with a peak intensity of a higher-order hydride structure, through observation of spectra of light scattered from the channel region.