Semiconductor device and memory device

Patent metadata

Field	Value
Publication number	US-11211461-B2
Application number	US-201916693974-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Dec 28, 2018
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A semiconductor device having favorable electrical characteristics is provided. The semiconductor device includes an oxide semiconductor, a first insulator in contact with the oxide semiconductor, and a second insulator in contact with the first insulator. The first insulator includes excess oxygen. The second insulator has a function of trapping or fixing hydrogen. Hydrogen in the oxide semiconductor is bonded to the excess oxygen. The hydrogen bonded to the excess oxygen passes through the first insulator and is trapped or fixed in the second insulator. The excess oxygen bonded to the hydrogen remains in the first insulator as the excess oxygen.

First claim

What is claimed is:

1. A semiconductor device comprising:
a first insulator;
a first oxide semiconductor over the first insulator;
a source electrode and a drain electrode over the first oxide semiconductor;
a second oxide semiconductor over the first oxide semiconductor and between the source electrode and the drain electrode;
a gate insulator over the second oxide semiconductor and between the source electrode and the drain electrode; and
a gate electrode over the gate insulator and between the source electrode and the drain electrode;
a second insulator over the source electrode and the drain electrode and comprising an opening between the source electrode and the drain electrode;
a third insulator over and in contact with the second insulator; and
a fourth insulator over and in contact with the third insulator,
wherein the second oxide semiconductor, the gate insulator, and the gate electrode are positioned inside the opening of the second insulator, and
wherein the first insulator and the fourth insulator are in contact with each other in a region where the second insulator and the third insulator do not exist.

2. The semiconductor device according to claim 1 ,
wherein the second insulator comprises excess oxygen,
wherein the third insulator is configured to trap or fix hydrogen,
wherein the fourth insulator has a barrier property against hydrogen,
wherein hydrogen in the second oxide semiconductor is bonded to the excess oxygen,
wherein the hydrogen bonded to the excess oxygen passes through the second insulator and is trapped or fixed in the third insulator, and
wherein the excess oxygen bonded to the hydrogen remains in the second insulator as the excess oxygen.

3. The semiconductor device according to claim 1 , wherein the second oxide semiconductor comprises indium, gallium, and zinc.

4. The semiconductor device according to claim 1 ,
wherein the second insulator comprises silicon oxynitride, and
wherein the third insulator comprises aluminum oxide.

5. The semiconductor device according to claim 1 , wherein the fourth insulator comprises silicon nitride.

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Yamaguchi Daisuke
• Kawaguchi Shinobu
• Komatsu Yoshihiro
• Ohno Toshikazu
• Yamane Yasumasa
• Kanagawa Tomosato

Classifications

• H10D62/875

  being semiconductor metal oxide, e.g. InGaZnO (Group II-VI materials H10D62/86; Group I-VI materials H10D62/871; Pb compounds or alloys H10D62/874) · CPC title

• H10D30/6704

  having supplementary regions or layers in the thin films or in the insulated bulk substrates for controlling properties of the device · CPC title

• H10D30/6755 Primary

  Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate · CPC title

• H10D62/80 Primary

  characterised by the materials · CPC title

• H10D99/00 Primary

  Subject matter not provided for in other groups of this subclass · CPC title