US 9,806,201 B2Granted

Semiconductor device

AssigneeSemiconductor Energy Laboratory Co., Ltd.

InventorsShunpei Yamazaki, Yoshinori Yamada, Yusuke Nonaka, Masashi Oota, Yoichi Kurosawa, Noritaka Ishihara, Takashi Hamada, Mitsuhiro Ichijo, Yuji Egi

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Abstract

A method for forming an oxide that can be used as a semiconductor of a transistor or the like is provided. In particular, a method for forming an oxide with fewer defects such as grain boundaries is provided. One embodiment of the present invention is a semiconductor device including an oxide semiconductor, an insulator, and a conductor. The oxide semiconductor includes a region overlapping with the conductor with the insulator therebetween. The oxide semiconductor includes a crystal grain with an equivalent circle diameter of 1 nm or more and a crystal grain with an equivalent circle diameter less than 1 nm.

Claims15

Dependent claims

A semiconductor device comprising:

a first insulating film having a projection;
a first oxide semiconductor film;
a first conductor film over the first oxide semiconductor film;
a second conductor film over the first oxide semiconductor film;
a second oxide semiconductor film over the first conductor film, the second conductor film, and the first oxide semiconductor film;
a second insulating film over the second oxide semiconductor film;
and
a third conductor film over the second insulating film,
wherein the first oxide semiconductor film is located over the projection of the first insulating film,
wherein each of the second oxide semiconductor film, the first conductor film, and the second conductor film is in contact with a top surface and a side surface of the first oxide semiconductor film, and a side surface of the projection of the first insulating film,
wherein the first oxide semiconductor film comprises a crystal grain with an equivalent circle diameter of 1 nm or more and a crystal grain with an equivalent circle diameter less than 1 nm, and
wherein the first oxide semiconductor film comprises a region in which hydrogen concentration measured by secondary ion mass spectrometry is lower than 1×1019 atoms/cm3.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/636,477Filed 3 Mar 2015
Priority: JP 2014-0455307 Mar 2014
Published: US 2015/0255534 A110 Sep 2015
Granted: 31 Oct 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H10D 30/6756
Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate: amorphous oxide semiconductors
H10B 41/70
Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates: the floating gate being an electrode shared by two or more…
H10D 30/6734
Multi-gate TFTs: having gate electrodes arranged on both top and bottom sides of the channel, e.g. dual-gate TFTs
H10D 30/6755
Characterised by the active materials: oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate