Light emitting element and manufacturing method thereof, and light emitting device using the light emitting element

Abstract

A light-emitting element has a layer including an organic material between a first electrode and a second electrode, and further has a layer including a metal oxide between the second electrode and the layer including the organic material, where these electrodes and layers are laminated so that the second electrode is formed later than the first electrode. The light-emitting element is suppressed damage caused to a layer including an organic material during deposition by sputtering and a phenomenon such as short circuit between electrodes.

1 . (canceled) 
     
     
         2 . A semiconductor device comprising:
 a first transistor;   a second transistor;   a third transistor;   a fourth transistor;   a capacitor; and   a light-emitting element,   wherein one of a source and drain of the first transistor is electrically connected to one of a source and a drain of the second transistor,   wherein the other one of the source and the drain of the second transistor is electrically connected to the light-emitting element,   wherein a gate of the first transistor is electrically connected to one of a source and a drain of the third transistor,   wherein the gate of the first transistor is electrically connected to one of a source and a drain of the fourth transistor, and   wherein the gate of the first transistor is electrically connected to an electrode of the capacitor.   
     
     
         3 . The semiconductor device according to  claim 2 , wherein a channel formation region of the first transistor overlaps a line electrically connected to the other one of the source and drain of the first transistor. 
     
     
         4 . The semiconductor device according to  claim 2 , wherein the first transistor is a driving transistor. 
     
     
         5 . The semiconductor device according to  claim 2 ,
 wherein a channel formation region of the first transistor comprises polycrystalline silicon,   wherein a channel formation region of the second transistor comprises polycrystalline silicon,   wherein a channel formation region of the third transistor comprises polycrystalline silicon, and   wherein a channel formation region of the fourth transistor comprises polycrystalline silicon.   
     
     
         6 . The semiconductor device according to  claim 2 , further comprising a substrate,
 wherein the substrate is made of any one of glass and plastic.   
     
     
         7 . The semiconductor device according to  claim 2 , the light-emitting element comprising:
 an anode;   a cathode;   a first layer comprising an organic material between the anode and the cathode; and   a second layer comprising a metal oxide and an electron injecting material between the cathode and the first layer,   wherein the second layer is in contact with the cathode, and   wherein the first layer is in contact with the second layer.   
     
     
         8 . The semiconductor device according to  claim 2 , wherein a channel formation region of the second transistor includes a U-shaped portion. 
     
     
         9 . A semiconductor device comprising:
 a first transistor;   a second transistor;   a third transistor;   a light emitting layer; and   a line,   wherein one of a source and drain of the first transistor is electrically connected to the light-emitting element,   wherein a gate of the first transistor is electrically connected to one of a source and a drain of the second transistor,   wherein the gate of the first transistor is electrically connected to one of a source and a drain of the third transistor,   wherein a channel formation region of the first transistor overlaps a line electrically connected to the other one of the source and the drain of the first transistor, and   wherein the channel formation region of the first transistor includes a U-shaped portion.   
     
     
         10 . The semiconductor device according to  claim 9 , wherein the first transistor is a driving transistor. 
     
     
         11 . The semiconductor device according to  claim 9 ,
 wherein the channel formation region of the first transistor comprises polycrystalline silicon,   wherein a channel formation region of the second transistor comprises polycrystalline silicon, and   wherein a channel formation region of the third transistor comprises polycrystalline silicon.   
     
     
         12 . The semiconductor device according to  claim 9 , further comprising a substrate,
 wherein the substrate is selected from any one of glass and plastic.   
     
     
         13 . The semiconductor device according to  claim 9 , the light-emitting element comprising:
 an anode;   a cathode;   a first layer comprising an organic material between the anode and the cathode;   and a second layer comprising a metal oxide and an electron injecting material between the cathode and the first layer,   wherein the second layer is in contact with the cathode, and   wherein the first layer is in contact with the second layer.