SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20110101335A1
• Filed: 10/26/2010
• Published: 05/05/2011
• Est. Priority Date: 10/30/2009
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: TAKAHASHI, Masahiro, MIYANAGA, Akiharu, YAMAZAKI, Shunpei, SAKATA, Junichiro, KISHIDA, Hideyuki
• Application Number:
  US12/912,196
• Publication Number:
  US 20110101335A1
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/42364 characterised by the insulating layer, e.g. thickness or uniformity H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• 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

An object is to provide a semiconductor device including an oxide semiconductor with stable electric characteristics can be provided. An insulating layer having many defects typified by dangling bonds is formed over an oxide semiconductor layer with an oxygen-excess mixed region or an oxygen-excess oxide insulating layer interposed therebetween, whereby impurities in the oxide semiconductor layer, such as hydrogen or moisture (a hydrogen atom or a compound including a hydrogen atom such as H₂O), are moved through the oxygen-excess mixed region or oxygen-excess oxide insulating layer and diffused into the insulating layer. Thus, the impurity concentration of the oxide semiconductor layer is reduced.

Claims

1. A semiconductor device comprising:

a transistor comprising a gate electrode layer, a gate insulating layer, an oxide semiconductor layer, a source electrode layer, and a drain electrode layer;

an insulating layer having defects; and

an oxygen-excess oxide insulating layer between the oxide semiconductor layer and the insulating layer,

wherein the oxygen-excess oxide insulating layer is in contact with part of the oxide semiconductor layer, and

wherein the oxygen-excess oxide insulating layer is in contact with the insulating layer.

2. The semiconductor device according to claim 1,

wherein the insulating layer is configured to bind and stabilize an impurity diffused from the oxide semiconductor layer.

3. The semiconductor device according to claim 2,

wherein the impurity includes at least one of hydrogen, moisture, hydroxyl, and hydride.

4. The semiconductor device according to claim 1,

wherein the oxygen-excess oxide insulating layer is configured to bind and stabilize an impurity which is diffused from the oxide semiconductor layer.

5. The semiconductor device according to claim 4,

wherein the impurity includes at least one of hydrogen, moisture, hydroxyl, and hydride.

6. The semiconductor device according to claim 1,

wherein a thickness of the oxygen-excess oxide insulating layer is 0.1 nm to 30 nm.

7. The semiconductor device according to claim 1,

wherein the oxygen-excess oxide insulating layer is a silicon oxide layer which includes SiO_2+x, and

wherein x is equal to or greater than 0 and less than 3.

8. A semiconductor device comprising:

a transistor comprising a gate electrode layer, a gate insulating layer, an oxide semiconductor layer, a source electrode layer, and a drain electrode layer; and

an insulating layer having defects,

wherein an oxygen-excess mixed region is provided at an interface between the oxide semiconductor layer and the insulating layer,

wherein the insulating layer includes silicon, and

wherein the oxygen-excess mixed region includes oxygen, silicon, and at least one of metal elements included in the oxide semiconductor layer.

9. The semiconductor device according to claim 8,

wherein the insulating layer is configured to bind and stabilize an impurity diffused from the oxide semiconductor layer.

10. The semiconductor device according to claim 9,

wherein the impurity includes at least one of hydrogen, moisture, hydroxyl, and hydride.

11. The semiconductor device according to claim 8,

wherein the oxygen-excess mixed region is configured to bind and stabilize an impurity which is diffused from the oxide semiconductor layer.

12. The semiconductor device according to claim 11,

wherein the impurity includes at least one of hydrogen, moisture, hydroxyl, and hydride.

13. The semiconductor device according to claim 8, further comprising a protective insulating layer covering the insulating layer having defects.

14. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode layer over a substrate;

forming a gate insulating layer over the gate electrode layer;

providing the substrate into a process chamber under reduced pressure;

introducing a sputtering gas from which hydrogen and moisture are removed while removing moisture remaining in the process chamber to form an oxide semiconductor layer over the gate insulating layer;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer;

forming an oxygen-excess oxide insulating layer over the source electrode layer, the drain electrode layer, and the oxide semiconductor layer;

forming an insulating layer having defects over the oxygen-excess oxide insulating layer by a sputtering method; and

heating the substrate to make an impurity included in the oxide semiconductor layer move through the oxygen-excess oxide insulating layer and diffuse into the insulating layer having defects.

15. The method for manufacturing a semiconductor device according to claim 14,

wherein the impurity includes at least one of hydrogen, moisture, hydroxyl, and hydride.

16. The method for manufacturing a semiconductor device according to claim 14,

wherein the process chamber where the oxygen-excess oxide insulating layer and the insulating layer having defects are formed is evacuated with a cryopump to remove remaining moisture.

17. The method for manufacturing a semiconductor device according to claim 14, further comprising forming a protective insulating layer over the insulating layer having defects.

18. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode layer over a substrate;

forming a gate insulating layer over the gate electrode layer;

providing the substrate into a process chamber under reduced pressure;

introducing a sputtering gas from which hydrogen and moisture are removed while removing moisture remaining in the process chamber to form an oxide semiconductor layer over the gate insulating layer;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer;

forming an insulating layer having defects over the oxide semiconductor layer by a sputtering method, whereby forming an oxygen-excess mixed region provided at an interface between the oxide semiconductor layer and the insulating layer; and

heating the substrate to make an impurity included in the oxide semiconductor layer move through the oxygen-excess mixed region and diffuse into the insulating layer having defects.

19. The method for manufacturing a semiconductor device according to claim 18,

wherein the impurity includes at least one of hydrogen, moisture, hydroxyl, and hydride.

20. The method for manufacturing a semiconductor device according to claim 18,

wherein the process chamber where the insulating layer having defects are formed is evacuated with a cryopump to remove remaining moisture.

21. The method for manufacturing a semiconductor device according to claim 18, further comprising the step of forming a protective insulating layer over the insulating layer having defects.