Titanium disulfide thin film and process for fabricating the same

• US 4,572,873 A
• Filed: 02/19/1985
• Issued: 02/25/1986
• Est. Priority Date: 09/13/1982
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kanehori, Keiichi, Kudo, Tetsuichi, Miyauchi, Katsuki
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/702,661
• Time in Patent Office: 371 Days
• Field of Search: 427/255, 427/255.1, 427/255.2, 427/126.1, 427/126.2, 427/419.7, 428/698, 428/426, 428/432, 428/411, 428/446, 428/701, 423/561 R
• US Class Current: 428/432
• CPC Class Codes: C23C 16/305 Sulfides, selenides, or tellurides
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/46 Sulfur-, selenium- or tellurium-containing compounds
• CPC Class Codes: C30B 29/605 Products containing multiple oriented crystallites, e.g. columnar crystallites
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/1397 of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/581 Chalcogenides or intercalation compounds thereof
• CPC Class Codes: H01M 4/5815 Sulfides
• CPC Class Codes: H01M 6/185 with oxides, hydroxides or oxysalts as solid electrolytes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention relates to a titanium disulfide film fabricated on a substrate, where crystallites of titanium disulfide is oriented at an angle of their c-axis to the substrate surface of not more than 45°, and to a process for fabricating the film, where the film is prepared by chemical vapor deposition from TiCl₄ and H₂ S as source gases under an inner pressure of reaction tube of 30 kPa or less.

Claims

1. A titanium disulfide film fabricated by chemical vapor deposition on a substrate, which comprises crystallites of titanium disulfide each being oriented at an angle of its c-axis to the substrate surface of not more than 45°

on average.

2. A titanium disulfide film according to claim 1, wherein the titanium disulfide film has a film density of 70% or higher.

7. A titanium disulfide film according to claim 1, wherein the titanium disulfide film has a thickness of from 1 μ

m to at least 10 μ

m and flatness such that a difference in the level on a surface of the film must be less than 0.5 μ

m from the level of an average film thickness.

8. A titanium disulfide film according to claim 1, wherein the substrate is made of a material selected from the group consisting of quartz, silicon and alumina.

11. A titanium disulfide film according to claim 1, wherein the crystallites in the titanium disulfide film are oriented to an angle of their c-axis to the substrate surface of not more than 30°

.

13. A titanium disulfide film according to claim 1, wherein each of said crystallites are of a size such that it extends from the substrate surface to the film surface.

15. A titanium disulfide film fabricated on a substrate according to claim 8, wherein said substrate is made of silicon.

3. A process for fabricating a titanium disulfide film on a substrate, which comprises forming a titanium disulfide film in which crystallites of titanium disulfide are oriented at an angle of their c-axis to the substrate surface of not more than 45°

on average on a substrate from titanium tetrachloride and hydrogen sulfide as source gases by chemical vapor deposition under an inner pressure of a reaction system, for forming the titanium disulfide, of 30 kPa or less and at a substrate temperature of 350°

-650°

C.

4. A process according to claim 3, wherein a concentration ratio of the hydrogen sulfide to the titanium tetrachloride is in a range of 3-20.

5. A process according to claim 3, wherein He or Ar is used as a carrier gas for the titanium tetrachloride and the hydrogen sulfide.

6. A process according to claim 3, wherein the substrate temperature is in a range of 420°

-600°

C.

9. A process according to claim 3, wherein said reaction system comprises a reaction tube in which the substrate is located and a mixture of the source gases is introduced into the reaction tube to effect chemical vapor deposition of the titanium disulfide film onto the substrate heated to said substrate temperature.

10. A process according to claim 9, wherein the mixture of titanium tetrachloride and hydrogen sulfide source gases has a concentration ratio of H₂ S/TiCl₄ of from 3 to 20.

12. A process according to claim 4, wherein He or Ar is used as a carrier gas for the titanium tetrachloride and the hydrogen sulfide.

14. A process according to claim 3, wherein the inner pressure of the reaction system is 1.5 kPa or less.