Semiconductor device having different types of thin film transistors

• US 9,941,413 B2
• Filed: 05/12/2016
• Issued: 04/10/2018
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Takahashi, Kei, Ito, Yoshiaki
• Primary Examiner(s): Hu, Shouxiang
• Application Number:
  US15/153,119
• Publication Number:
  US 20160260839A1
• Time in Patent Office: 698 Days
• Field of Search: 257 43, 257 64, 257 66, 257 72, 257E29068
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/0611 for increasing or controlling the breakdown voltage of reverse biased devices H01L29/0661 takes precedence
• 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 29/41733 for thin film transistors with insulated gate
• 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 29/66477 with an insulated gate, i.e. MISFET
• 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 29/78618 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 29/78642 Vertical transistors
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel
• 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 29/78693 the semiconducting oxide being amorphous
• 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

It is an object to provide a semiconductor device having a new productive semiconductor material and a new structure. The semiconductor device includes a first conductive layer over a substrate, a first insulating layer which covers the first conductive layer, an oxide semiconductor layer over the first insulating layer that overlaps with part of the first conductive layer and has a crystal region in a surface part, second and third conductive layers formed in contact with the oxide semiconductor layer, an insulating layer which covers the oxide semiconductor layer and the second and third conductive layers, and a fourth conductive layer over the insulating layer that overlaps with part of the oxide semiconductor layer.

Claims

1. A semiconductor device comprising:

a first transistor over a substrate, the first transistor comprising;

a first conductive layer over the substrate;

a first insulating layer over the first conductive layer;

a first oxide semiconductor layer over the first insulating layer, the first oxide semiconductor layer overlapping with the first conductive layer;

a second conductive layer as one of a first source electrode and a first drain electrode in contact with a first portion on a top surface of the first oxide semiconductor layer;

a third conductive layer as the other of the first source electrode and the first drain electrode in contact with a second portion on the top surface of the first oxide semiconductor layer;

a second insulating layer over the first oxide semiconductor layer, the second conductive layer, and the third conductive layer; and

a fourth conductive layer as a first gate electrode over the second insulating layer, the fourth conductive layer overlapping with the first oxide semiconductor layer with the second insulating layer interposed therebetween; and

a second transistor over the substrate, the second transistor comprising;

a fifth conductive layer as one of a second source electrode and a second drain electrode over the substrate;

a sixth conductive layer as the other of the second source electrode and the second drain electrode over the substrate;

a second oxide semiconductor layer in contact with the fifth conductive layer and the sixth conductive layer, the second oxide semiconductor layer being over the fifth conductive layer; and

a seventh conductive layer as a second gate electrode over the second oxide semiconductor layer, the seventh conductive layer overlapping with the second oxide semiconductor layer with the second insulating layer interposed therebetween,

wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer includes indium, gallium, and zinc,

wherein the fifth conductive layer includes a material which is the same as the first conductive layer, and the fifth conductive layer and the first conductive layer being on a same layer, and

wherein the seventh conductive layer includes a material which is the same as the fourth conductive layer.

2. The semiconductor device according to claim 1, wherein each of the second conductive layer and the third conductive layer includes tantalum nitride.

3. The semiconductor device according to claim 1, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer includes a crystal region.

4. The semiconductor device according to claim 1, wherein an upper surface of each of the first oxide semiconductor layer and the second oxide semiconductor layer is crystallized.

5. The semiconductor device according to claim 1, wherein the first conductive layer is electrically connected to the fourth conductive layer.

6. The semiconductor device according to claim 1, wherein a potential of the first conductive layer is a floating potential.

7. The semiconductor device according to claim 1, wherein a potential of the first conductive layer is a fixed potential.

8. The semiconductor device according to claim 1, wherein the fifth conductive layer is under the second oxide semiconductor layer and the sixth conductive layer is over the second oxide semiconductor layer.

9. A semiconductor device comprising:

a first transistor over a substrate, the first transistor comprising;

a first conductive layer over the substrate;

a first insulating layer over the first conductive layer;

a first oxide semiconductor layer over the first insulating layer, the first oxide semiconductor layer overlapping with the first conductive layer;

a second conductive layer as one of a first source electrode and a first drain electrode in contact with a first portion on a top surface of the first oxide semiconductor layer, the second conductive layer including tantalum nitride;

a third conductive layer as the other of the first source electrode and the first drain electrode in contact with a second portion on the top surface of the first oxide semiconductor layer, the third conductive layer including tantalum nitride;

a second insulating layer over the first oxide semiconductor layer, the second conductive layer, and the third conductive layer; and

a fourth conductive layer as a first gate electrode over the second insulating layer, the fourth conductive layer overlapping with the first oxide semiconductor layer with the second insulating layer interposed therebetween; and

a second transistor over the substrate, the second transistor comprising;

a fifth conductive layer as one of a second source electrode and a second drain electrode over the substrate;

a sixth conductive layer as the other of the second source electrode and the second drain electrode over the substrate;

a second oxide semiconductor layer in contact with the fifth conductive layer and the sixth conductive layer, the second oxide semiconductor layer being over the fifth conductive layer; and

a seventh conductive layer as a second gate electrode over the second oxide semiconductor layer, the seventh conductive layer overlapping with the second oxide semiconductor layer with the second insulating layer interposed therebetween,

wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer includes indium, gallium, and zinc,

wherein the fifth conductive layer includes a material which is the same as the first conductive layer, and the fifth conductive layer and the first conductive layer being on a same layer, and

wherein each of the fourth conductive layer and the seventh conductive layer is a layered structure and includes a light-transmitting oxide conductive material.

10. The semiconductor device according to claim 9, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer includes a crystal region.

11. The semiconductor device according to claim 9, wherein an upper surface of each of the first oxide semiconductor layer and the second oxide semiconductor layer is crystallized.

12. The semiconductor device according to claim 9, wherein the first conductive layer is electrically connected to the fourth conductive layer.

13. The semiconductor device according to claim 9, wherein a potential of the first conductive layer is a floating potential.

14. The semiconductor device according to claim 9, wherein a potential of the first conductive layer is a fixed potential.

15. The semiconductor device according to claim 9, wherein the fifth conductive layer is under the second oxide semiconductor layer and the sixth conductive layer is over the second oxide semiconductor layer.