FIELD-EFFECT TRANSISTOR

• US 20090189153A1
• Filed: 09/05/2006
• Published: 07/30/2009
• Est. Priority Date: 09/16/2005
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Den, Toru, Iwasaki, Tatsuya, Itagaki, Naho
• Application Number:
  US12/064,302
• Publication Number:
  US 20090189153A1
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 29/26 including, apart from doping materials or other impurities, elements provided for in two or more of the groups H01L29/16, H01L29/18, H01L29/20, H01L29/22, H01L29/24 , e.g. alloys
• CPC Class Codes: H01L 29/78 with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

Disclosed herein is a field-effect transistor comprising a channel comprised of an oxide semiconductor material including In and Zn. The atomic compositional ratio expressed by In/(In+Zn) is not less than 35 atomic % and not more than 55 atomic %. Ga is not included in the oxide semiconductor material or the atomic compositional ratio expressed by Ga/(In+Zn+Ga) is set to be 30 atomic % or lower when Ga is included therein. The transistor has improved S-value and field-effect mobility.

Claims

1. A field-effect transistor, comprising a channel made of an oxide semiconductor material including In and Zn, wherein a atomic compositional ratio expressed by In/(In+Zn) is not less than 35 atomic % and not more than 55 atomic %;

and wherein Ga is not included in the oxide semiconductor material or a atomic compositional ratio expressed by Ga/(In+Zn+Ga) is 30 atomic % or lower when Ga is included therein.

2. A field-effect transistor according to claim 1, wherein the atomic compositional ratio expressed by Ga/(In+Zn+Ga) is n 15 atomic % or lower.

3. A field-effect transistor according to claim 1, wherein the atomic compositional ratio expressed by Ga/(In+Zn+Ga) is 5 atomic % or lower.

4. A field-effect transistor according to claim 1, wherein the atomic compositional ratio expressed by Ga/(In+Zn+Ga) is not less than 5 atomic % and not more than 15 atomic %.

5. A field-effect transistor according to claim 1, wherein the atomic compositional ratio expressed by In/(In+Zn) is 40 atomic % or more.

6. A field-effect transistor according to claim 1, wherein the atomic compositional ratio expressed by In/(In+Zn) is 50 atomic % or lower.

7. A field-effect transistor comprising a channel made of an oxide semiconductor including In and Zn, wherein the oxide semiconductor has a composition in a region surrounded by Y, h, i, and k shown in Table 1:

TABLE 1

8. A field-effect transistor comprising a channel made of an oxide semiconductor including In and Zn,

wherein the oxide semiconductor has a composition in a region surrounded by a, f, i, and k shown in Table 1 with respect to In, Zn, and Ga and further includes Sn added thereto:

TABLE 1

9. A field-effect transistor according to claim 8, wherein a atomic compositional ratio expressed by Sn/(Sn+In+Zn) is 0.1 atomic % or higher and 20 atomic % or lower.