US 9,812,578 B2
Thin film transistor and display device using the same
Norihiro Uemura, Mobara (JP); Takeshi Noda, Mobara (JP); Hidekazu Miyake, Mobara (JP); and Isao Suzumura, Tokyo (JP)
Assigned to Japan Display Inc., Tokyo (JP)
Filed by Japan Display Inc., Tokyo (JP)
Filed on Oct. 22, 2015, as Appl. No. 14/920,647.
Application 14/920,647 is a continuation of application No. 13/851,162, filed on Mar. 27, 2013, granted, now 9,209,306.
Claims priority of application No. 2012-098764 (JP), filed on Apr. 24, 2012.
Prior Publication US 2016/0043232 A1, Feb. 11, 2016
Int. Cl. H01L 29/786 (2006.01); G02F 1/1368 (2006.01); G02F 1/1335 (2006.01); H01L 27/12 (2006.01)
CPC H01L 29/78606 (2013.01) [G02F 1/1368 (2013.01); G02F 1/133602 (2013.01); H01L 27/1225 (2013.01); H01L 29/7869 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A thin film transistor comprising:
an insulating substrate,
a gate electrode provided on an upper surface of the insulating substrate,
a gate insulating film formed so as to cover the gate electrode,
an oxide semiconductor layer provided on the gate insulating film,
a source electrode and a drain electrode provided so as to contact with a first region of the oxide semiconductor layer, and
a protective layer provided so as to contact with a channel region of the oxide semiconductor layer, and
wherein the protective layer includes a first side contacting the channel region of the oxide semiconductor layer, and a second side distant from the oxide semiconductor layer,
wherein the first side is formed in direct contact with the source electrode and the drain electrode,
wherein the second side is made of the same composition element as the first side and located above the first side,
wherein a density of the first side is different from a density of the second side,
wherein the gate electrode has a first protruding edge and a second protruding edge in a channel length direction,
wherein the first protruding edge and the second protruding edge protrude to the outside of the oxide semiconductor layer in a plan view,
wherein the protective layer covers an upper surface of the source electrode, an upper surface of the drain electrode, and the channel region, and
wherein the first side and the second side of the protective layer overlaps the first protruding edge and the second protruding edge,
the second side, the first side, the source electrode and the drain electrode, the oxide semiconductor layer, the gate insulating film, and the gate electrode are arranged in that order.