Transistor Including a Deposited Channel Region Having a Doped Portion

• US 20070267699A1
• Filed: 07/24/2007
• Published: 11/22/2007
• Est. Priority Date: 07/25/2003
• Status: Active Grant

• Current Assignee: Randy Hoffman
• Original Assignee: Randy Hoffman
• Inventors: Hoffman, Randy
• Granted Patent: US 7,564,055 B2
• Time in Patent Office: Days
• US Class Current: 257/347
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 29/105 with vertical doping variation H01L29/7827 takes precedence
• CPC Class Codes: H01L 29/1054 with a variation of the composition, e.g. channel with strained layer for increasing the mobility
• CPC Class Codes: H01L 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 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
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

A transistor having a gate electrode, a source electrode, a drain electrode, a dielectric material and a channel region disposed between the source electrode and drain electrode. The channel region includes a portion doped with an impurity to change the fixed charge density within the portion relative to a remainder of the channel region.

Claims

1. A thin-film transistor, comprising:

a source electrode;

a drain electrode;

a gate electrode;

a deposited thin-film channel region having a portion doped with an impurity to change the fixed charge density within the portion relative to a remainder of the channel region and disposed between the source and drain electrode; and

a dielectric material electrically separating the gate electrode from the channel region.

2. The thin-film transistor of claim 1, where the portion of the channel region is disposed between the remainder of the channel region and the dielectric material.

3. The thin-film transistor of claim 1, where the dielectric material includes silicon dioxide.

23. The thin-film transistor of claim 1, where the channel region comprises a controllable electrical pathway between the source electrode and drain electrode.

4. A thin-film transistor, comprising:

a source electrode;

a drain electrode;

a gate electrode;

a deposited thin-film channel region having a portion doped with an impurity to change the fixed charge density within the portion relative to a remainder of the channel region and disposed between the source and drain electrode, where the channel region is a deposited layer fabricated from a binary oxide semiconductor material; and

a dielectric material electrically separating the gate electrode from the channel region.

5. The thin-film transistor of claim 4, where the channel region is fabricated from zinc oxide.

6. The thin-film transistor of claim 4, where the impurity is a donor-type impurity which increases the positive fixed charge density within the portion of the channel region.

7. The thin-film transistor of claim 4, where the impurity is an acceptor-type impurity which increases the negative fixed charge density within the portion of the channel region.

8. The thin-film transistor of claim 5, where the impurity is a donor-type impurity which increases the positive fixed charge density within the portion of the channel region.

9. The thin-film transistor of claim 8, where the donor-type impurity is selected from the group consisting of aluminum, boron, gallium, indium, fluorine and chlorine.

10. The thin-film transistor of claim 8, where the donor-type impurity is aluminum.

11. The thin-film transistor of claim 5, where the impurity is an acceptor-type impurity which increases the negative fixed charge density within the portion of the channel region.

12. The thin-film transistor of claim 11, where the acceptor-type impurity is selected from the group consisting of nitrogen, copper, phosphorous, arsenic, antimony, lithium, sodium and potassium.

13. The thin-film transistor of claim 4, where the channel region is fabricated from indium oxide.

14. The thin-film transistor of claim 13, where the impurity is a donor-type impurity which increases the positive fixed charge density within the portion of the channel region.

15. The thin-film transistor of claim 14, where the donor-type impurity is selected from the group consisting of silicon, germanium, tin, lead, fluorine and chlorine.

16. The thin-film transistor of claim 13, where the impurity is an acceptor-type impurity which increases the negative fixed charge density within the portion of the channel region.

17. The thin-film transistor of claim 16, where the acceptor-type impurity is selected from the group consisting of nitrogen, phosphorous, arsenic and antimony.

18. The thin-film transistor of claim 4, where the channel region is fabricated from tin oxide.

19. The thin-film transistor of claim 18, where the impurity is a donor-type impurity which increases the positive fixed charge density within the portion of the channel region.

20. The thin-film transistor of claim 19, where the donor-type impurity is selected from the group consisting of arsenic, antimony, bismuth, fluorine and chlorine.

21. The thin-film transistor of claim 18, where the impurity is an acceptor-type impurity which increases the negative fixed charge density within the portion of the channel region.

22. The thin-film transistor of claim 21, where the acceptor-type impurity is selected from the group consisting of boron, aluminum, gallium, indium, nitrogen, phosphorus, arsenic and antimony.

24-46. -46. (canceled)