Semiconductor device manufacturing method

Abstract

According to one embodiment, a method for manufacturing a semiconductor device includes the steps of forming a conductive layer comprising a metal element and oxygen, and forming a first film on the conductive layer. The method further includes the steps of forming a recess within the first film, and forming a second film within the recess. The method further includes the steps of processing the second film within the recess using a first gas comprising Cl (chlorine) to expose the surface of the conductive layer within the recess. The method further includes the steps of oxidizing the surface of the conductive layer exposed within the recess, and forming a semiconductor layer within the recess that contacts the oxidized surface of the conductive layer.

Claims

1. A method for manufacturing a semiconductor device, comprising the following steps: forming a conductive layer comprising a metal element and oxygen; forming a first film on the conductive layer; forming a recess in the first film; forming a second film in the recess; etching the second film in the recess using a first gas containing Cl (chlorine) to expose the surface of the conductive layer in the recess; oxidizing the surface of the conductive layer exposed in the recess; and forming a semiconductor layer in the recess that contacts the oxidized surface of the conductive layer.

2. A method for manufacturing a semiconductor device as described in claim 1, wherein the conductive layer is an oxide conductive layer.

3. A method for manufacturing a semiconductor device as described in claim 1, wherein the aforementioned metal element is In (indium), Sn (tin), Zn (zinc), or Ti (titanium).

4. A method for manufacturing a semiconductor device as described in claim 1, wherein the conductive layer is an ITO (indium tin oxide) layer.

5. A method for manufacturing a semiconductor device as described in claim 1, wherein the semiconductor layer is an oxide semiconductor layer.

6. A method for manufacturing a semiconductor device as claimed in claim 1, wherein the semiconductor layer comprises In (indium), Ga (gallium) and Zn (zinc).

7. A method for manufacturing a semiconductor device as described in claim 1, wherein the semiconductor layer is an IGZO layer.

8. A method for manufacturing a semiconductor device as claimed in claim 1, wherein the first film comprises a first insulating film formed on the conductive layer, a wiring layer formed on the first insulating film, and a second insulating film formed on the wiring layer, the second film comprising a third insulating film, and the semiconductor layer being formed on the side of the wiring layer within the recess through the third insulating film.

9. A method for manufacturing a semiconductor device as claimed in claim 8, wherein the third insulating film comprises a fourth insulating film containing oxygen and a fifth insulating film containing nitrogen.

10. A method for manufacturing a semiconductor device as claimed in claim 1, wherein when the recess is formed in the first film, a first portion of the recess is formed in the first film; when the second film is formed in the recess, the second film is formed on the side surface and bottom surface of the first portion of the recess; and when the second film in the recess is etched, the second film formed on the bottom surface of the first portion of the recess is removed to form a second portion of the recess below the first portion of the recess.

11. A method for manufacturing a semiconductor device as claimed in claim 10, wherein the first portion of the recess is formed to not penetrate the first film, and the second portion of the recess is formed to penetrate the second film and the first film.

12. A method for manufacturing a semiconductor device as claimed in claim 10, wherein the first portion of the recess is formed to penetrate the first film, and the second portion of the recess is formed to penetrate the second film.

13. A method for manufacturing a semiconductor device as claimed in claim 1, wherein the second film within the recess is etched by plasma generated from the first gas.

14. A method for manufacturing a semiconductor device as claimed in claim 1, wherein the first gas comprises Cl2 gas, HCl gas, BCl3 gas or SiCl4 gas (H represents hydrogen, B represents boron and Si represents silicon).

15. A method for manufacturing a semiconductor device as described in claim 1, wherein the first gas does not contain F (fluorine).

16. A method for manufacturing a semiconductor device as claimed in claim 1, wherein the oxidation is performed by plasma oxidation or thermal oxidation.

17. A method for manufacturing a semiconductor device as claimed in claim 1, wherein the oxidation is performed at 50 to 400°C.

18. A method for manufacturing a semiconductor device, comprising the steps of: forming a conductive layer comprising a metal element and oxygen; forming a film on the conductive layer; etching the film using a first gas comprising a first element to expose the surface of the conductive layer from the film; oxidizing the surface of the conductive layer exposed from the film, wherein the bonding energy between the metal element and the first element is less than the bonding energy between the metal element and oxygen.

19. A method for manufacturing a semiconductor device as described in claim 18, wherein the metal element is In (indium) and the first element is Cl (chlorine).

20. A method for manufacturing a semiconductor device as claimed in claim 18, further comprising the step of forming a semiconductor layer on the oxidized surface of the conductive layer.

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