Semiconductor Device

• US 20140299874A1
• Filed: 04/02/2014
• Published: 10/09/2014
• Est. Priority Date: 04/03/2013
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Application Number:
  US14/243,257
• Publication Number:
  US 20140299874A1
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

To provide a semiconductor device including, over the same substrate, a transistor and a resistor each including an oxide semiconductor. A semiconductor device includes a resistor having a first oxide semiconductor layer covered with a nitride insulating layer containing hydrogen and a transistor having a second oxide semiconductor layer which is covered with an oxide insulating layer, has the same composition as the first oxide semiconductor layer, and has a different carrier density from the first oxide semiconductor layer. The first oxide semiconductor layer has higher carrier density than the second oxide semiconductor layer by treatment for increasing an impurity concentration. The treatment is performed on an entire surface of the first oxide semiconductor layer processed into an island shape. Therefore, in the first oxide semiconductor layer, regions contacting the nitride insulating layer and regions contacting electrode layers in contact holes of the nitride insulating layer have the same conductivity.

Claims

1. A semiconductor device comprising:

a resistor and a transistor over a substrate,

wherein the resistor comprises;

a first oxide semiconductor layer;

a nitride insulating layer covering the first oxide semiconductor layer; and

a first electrode and a second electrode electrically connected to the first oxide semiconductor layer in contact holes provided in the nitride insulating layer,

wherein the transistor comprises;

a gate electrode layer;

a second oxide semiconductor layer overlapping the gate electrode layer;

an insulating layer between the gate electrode layer and the second oxide semiconductor layer;

an oxide insulating layer covering the second oxide semiconductor layer; and

a third electrode and a fourth electrode electrically connected to the second oxide semiconductor layer in contact holes provided in the oxide insulating layer, and

wherein a carrier density of the first oxide semiconductor layer is higher than a carrier density of the second oxide semiconductor layer.

2. The semiconductor device according to claim 1,

wherein a length of a path through which a carrier flows in the resistor is longer than a length of a path through which a carrier flows in the transistor.

3. The semiconductor device according to claim 1,

wherein the transistor is included in a pixel portion, and

wherein the resistor is included in a driver circuit portion.

4. The semiconductor device according to claim 1, wherein the first oxide semiconductor layer has a same composition as the second oxide semiconductor layer.

5. The semiconductor device according to claim 1, wherein the semiconductor device is one selected from the group consisting of a mobile computer, a portable image regenerating device, a goggle-type display, a portable game machine, a digital camera, and a television set.

6. A semiconductor device comprising:

a resistor and a transistor over a substrate,

wherein the resistor comprises;

a first nitride insulating layer;

a first oxide semiconductor layer over the first nitride insulating layer;

a second nitride insulating layer covering the first oxide semiconductor layer; and

a first electrode and a second electrode electrically connected to the first oxide semiconductor layer in contact holes provided in the second nitride insulating layer,

wherein the transistor comprises;

a gate electrode layer;

the first nitride insulating layer over the gate electrode layer;

a first oxide insulating layer over the first nitride insulating layer;

a second oxide semiconductor layer overlapping the gate electrode layer with the first nitride insulating layer and the first oxide insulating layer interposed therebetween;

a second oxide insulating layer covering the second oxide semiconductor layer;

the second nitride insulating layer over the second oxide insulating layer; and

a third electrode and a fourth electrode electrically connected to the second oxide semiconductor layer in contact holes provided in the second nitride insulating layer and the second oxide insulating layer, and

wherein a carrier density of the first oxide semiconductor layer is higher than a carrier density of the second oxide semiconductor layer.

7. The semiconductor device according to claim 6,

wherein the resistor includes the first oxide insulating layer between the first nitride insulating layer and the first oxide semiconductor layer.

8. The semiconductor device according to claim 6,

wherein a length of a path through which a carrier flows in the resistor is longer than a length of a path through which a carrier flows in the transistor.

9. The semiconductor device according to claim 6,

wherein the transistor is included in a pixel portion, and

wherein the resistor is included in a driver circuit portion.

10. The semiconductor device according to claim 6, wherein the first oxide semiconductor layer has a same composition as the second oxide semiconductor layer.

11. The semiconductor device according to claim 6, wherein the semiconductor device is one selected from the group consisting of a mobile computer, a portable image regenerating device, a goggle-type display, a portable game machine, a digital camera, and a television set.