Field-effect transistor including transparent oxide and light-shielding member, and display utilizing the transistor

Abstract

A field-effect transistor includes a substrate, a source electrode, a drain electrode, a gate electrode, a gate-insulating film, and an active layer. The active layer contains an oxide having a transmittance of 70% or more in the wavelength range of 400 to 800 nm. A light-shielding member is provided as a light-shielding structure for the active layer, for example, on the bottom face of the substrate.

1 - 20 . (canceled) 
     
     
         21 . An article with a field-effect transistor comprising:
 a substrate;   a field-effect transistor disposed on the substrate,   wherein the field-effect transistor comprises an active layer which contains an oxide containing at least one selected from the group consisting of In—Ga—Zn oxide, Sn—In—Zn oxide, In oxide, In—Sn oxide, In—Ga oxide, and In—Zn oxide; and   a light-shielding member formed so as to shield the active layer from light which enters the active layer,   wherein the light-shielding member has a light-shielding property to light having any wavelength in a range of 400 to 500 nm and has a transmittance of 30% or less in any wavelength in a range of 400 to 500 nm.   
     
     
         22 . An article according to  claim 21 , wherein the light-shielding member achieves the light shielding by absorbing or reflecting light having a predetermined wave length or combination of the absorption and reflection of light. 
     
     
         23 . An article according to  claim 21 , wherein the light-shielding member comprises an insulating layer. 
     
     
         24 . An article according to  claim 23 , wherein the insulating layer is formed of an organic material. 
     
     
         25 . A display comprising:
 a light-emitting layer which is electrically connected to an electrode; and   a field-effect transistor according to  claim 21 ,   wherein a drain electrode of the field-effect transistor is electrically connected to the electrode; and   wherein a current flowing into the light-emitting layer from the electrode is controlled by a voltage of a gate electrode of the field-effect transistor.   
     
     
         26 . The display according to  claim 25 , wherein the light-emitting layer comprises an organic material. 
     
     
         27 . The display according to  claim 26 , wherein the field-effect transistor is formed on a flexible substrate. 
     
     
         28 . The display according to  claim 27 , wherein the flexible substrate is a plastic film. 
     
     
         29 . A display comprising:
 a liquid-crystal layer which is sandwiched in between a first electrode and a second electrode; and   a field-effect transistor according to  claim 21 ,   wherein a drain electrode of the field-effect transistor is electrically connected to the electrode; and   wherein a voltage applied between the first electrode and the second electrode is controlled by a voltage of a gate electrode of the field-effect transistor.   
     
     
         30 . A field-effect transistor comprising a substrate, a source electrode, a drain electrode, a gate electrode, a gate-insulating film, and an active layer,
 wherein the active layer contains an oxide having a transmittance of 70% or more in the wavelength range of 400 to 800 nm,   wherein a light-shielding member is formed so as to shield the active layer from light which enters the active layer,   wherein the oxide satisfies the following conditions:   (a) the oxide contains at least one selected from the group consisting of In—Ga—Zn oxide, Sn—In—Zn oxide, In oxide, In—Sn oxide, In—Ga oxide, and In—Zn oxide;   (b) an electron carrier concentration is lower than 10 18 /cm 3 , and   wherein the light-shielding member has a light-shielding property to light having any wavelength in a range of 400 to 500 nm; and   (c) the light-shielding member has a transmittance of 30% or less in any wavelength in a range of 400 to 500 nm.   
     
     
         31 . A field-effect transistor according to  claim 30 , wherein the light-shielding member achieves the light shielding by absorbing or reflecting light having a predetermined wave length or combination of the absorption and reflection of light. 
     
     
         32 . The article according to  claim 30 , wherein the light-shielding member comprises an insulating layer. 
     
     
         33 . An article according to  claim 32 , wherein the insulating layer is formed of an organic material. 
     
     
         34 . A display comprising:
 a light-emitting layer which is electrically connected to an electrode; and   a field-effect transistor according to  claim 30 ,   wherein a drain electrode of the field-effect transistor is electrically connected to the electrode; and   wherein a current flowing into the light-emitting layer from the electrode is controlled by a voltage of a gate electrode of the field-effect transistor.   
     
     
         35 . The display according to  claim 34 , wherein the light-emitting layer comprises an organic material. 
     
     
         36 . The display according to  claim 35 , wherein the field-effect transistor is formed on a flexible substrate. 
     
     
         37 . The display according to  claim 36 , wherein the flexible substrate is a plastic film. 
     
     
         38 . A display comprising:
 a liquid-crystal layer which is sandwiched in between a first electrode and a second electrode; and   a field-effect transistor according to  claim 30 ,   wherein a drain electrode of the field-effect transistor is electrically connected to the electrode; and   wherein a voltage applied between the first electrode and the second electrode is controlled by a voltage of a gate electrode of the field-effect transistor.