Semiconductor device and manufacturing method thereof

• US 9,620,623 B2
• Filed: 07/29/2014
• Issued: 04/11/2017
• Est. Priority Date: 10/19/2011
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Hayakawa, Masahiko, Honda, Tatsuya
• Primary Examiner(s): Luu, Chuong A
• Assistant Examiner(s): Fortich, Rodolfo D
• Application Number:
  US14/445,462
• Publication Number:
  US 20140332807A1
• Time in Patent Office: 987 Days
• Field of Search: 257 43, 257192, 257 40, 257 57, 257 72
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: G02F 2203/64 Normally black display, i.e. the off state being black
• 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 27/14616 characterised by the channel of the transistor, e.g. channel having a doping gradient
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/49 Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET H01L29/435 takes precedence
• CPC Class Codes: H01L 29/66742 Thin film unipolar transistors
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

When a semiconductor device including a transistor in which a gate electrode layer, a gate insulating film, and an oxide semiconductor film are stacked and a source and drain electrode layers are provided in contact with the oxide semiconductor film is manufactured, after the formation of the gate electrode layer or the source and drain electrode layers by an etching step, a step of removing a residue remaining by the etching step and existing on a surface of the gate electrode layer or a surface of the oxide semiconductor film and in the vicinity of the surface is performed. The surface density of the residue on the surface of the oxide semiconductor film or the gate electrode layer can be 1×10¹³ atoms/cm² or lower.

Claims

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

forming a conductive film over an insulating surface;

forming a gate electrode by etching the conductive film using a gas including halogen;

removing a residue on the gate electrode after the step of forming the gate electrode;

forming a gate insulating film over the gate electrode after the step of removing the residue on the gate electrode;

forming an oxide semiconductor film over the gate insulating film; and

forming a source electrode and a drain electrode over the oxide semiconductor film,

wherein the oxide semiconductor film comprises indium, and

wherein the step of removing the residue is performed by a plasma treatment.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the residue comprises at least one of chlorine, fluorine, boron, phosphorus, aluminum, iron, and carbon.

3. The method for manufacturing a semiconductor device according to claim 1, wherein the gate electrode comprises at least one of molybdenum, titanium, tantalum, tungsten, aluminum, copper, chromium, neodymium, and scandium.

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

forming a first conductive film over an insulating surface;

forming a gate electrode by etching the first conductive film using a gas including halogen;

removing a residue on the gate electrode;

forming a gate insulating film over the gate electrode after the step of removing the residue on the gate electrode;

forming an oxide semiconductor film over the gate insulating film;

forming a second conductive film over the oxide semiconductor film;

forming a source electrode and a drain electrode by etching the second conductive film using a gas including halogen; and

removing a residue on the oxide semiconductor film after the step of forming the source electrode and the drain electrode.

5. The method for manufacturing a semiconductor device according to claim 4, wherein the step of removing the residue is performed by a plasma treatment.

6. The method for manufacturing a semiconductor device according to claim 4, wherein the step of removing the residue is performed by a treatment using a solution.

7. The method for manufacturing a semiconductor device according to claim 4, wherein the residue comprises at least one of chlorine, fluorine, boron, phosphorus, aluminum, iron, and carbon.

8. The method for manufacturing a semiconductor device according to claim 4, wherein the oxide semiconductor film comprises indium.

9. The method for manufacturing a semiconductor device according to claim 4, wherein the gate electrode comprises at least one of molybdenum, titanium, tantalum, tungsten, aluminum, copper, chromium, neodymium, and scandium.