Flexible display and method of manufacturing the same

Abstract

A substrate for a flexible display is disclosed. The substrate has a film stress range that does not affect an electronic device such as a thin film transistor, and includes a barrier layer having excellent oxygen and moisture blocking characteristics, and a method of manufacturing the substrate. The substrate includes: a plastic substrate having a glass transition temperature from about 350° C. to about 500° C.; and a barrier layer disposed on the plastic substrate, having a multi-layer structure, wherein at least one silicon oxide layer and at least one silicon nitride layer are alternately stacked on each other, and having a film stress from about −200 MPa to about 200 MPa due to the at least one silicon oxide layer and the at least one silicon nitride layer.

What is claimed is: 
     
         1 . A flexible display, comprising:
 a flexible substrate; and   a thin film transistor and emitting device formed on the flexible substrate;   wherein the flexible substrate comprising, a plastic substrate having a glass transition temperature from about 350° C. to about 500° C., the plastic substrate comprising a planar surface; and   a barrier layer comprising a major surface, substantially all area of which contacts the planar surface of the plastic substrate, the barrier layer having a multi-layer structure, which comprises at least one silicon oxide layer and at least one silicon nitride layer that are alternately stacked on each other, the at least one silicon nitride layer having a hydrogen atom content from about 13% to about 17%, the barrier layer having a film stress from about −2001 MPa to about 2001 MPa.   
     
     
         2 . The display of  claim 1 , wherein the barrier layer comprises:
 a first silicon oxide layer;   a silicon nitride layer stacked on the first silicon oxide layer; and   a second silicon oxide layer stacked on the silicon nitride layer.   
     
     
         3 . The display of  claim 1 , wherein the barrier layer comprises:
 a first silicon oxide layer;   a first silicon nitride layer stacked on the first silicon oxide layer;   a second silicon oxide layer stacked on the first silicon nitride layer;   a second silicon nitride layer stacked on the second silicon oxide layer; and   a third silicon oxide layer stacked on the second silicon nitride layer.   
     
     
         4 . The display of  claim 1 , wherein the barrier layer comprises:
 a first silicon oxide layer;   a first silicon nitride layer stacked on the first silicon oxide layer;   a second silicon oxide layer stacked on the first silicon nitride layer;   a second silicon nitride layer stacked on the second silicon oxide layer;   a third silicon oxide layer stacked on the second silicon nitride layer;   a third silicon nitride layer stacked on the third silicon oxide layer; and   a fourth silicon oxide layer stacked on the third silicon nitride layer.   
     
     
         5 . The display of  claim 1 , wherein the at least one silicon oxide layer has compressive film stress, and wherein the at least one silicon nitride layer has tensile film stress. 
     
     
         6 . The display of  claim 1 , wherein a film density of the at least one silicon nitride layer is from about 2.5 g/cm 3  to about 2.7 g/cm 3 . 
     
     
         7 . The display of  claim 1 , wherein a thickness of each of the at least one silicon nitride layer is from about 200 Å to about 1000 Å. 
     
     
         8 . The display of  claim 1 , wherein a thickness of each of the at least one silicon oxide layer is from about 1000 Å to about 3000 Å. 
     
     
         9 . The display of  claim 1 , wherein the plastic substrate comprises polyimide. 
     
     
         10 . A method of manufacturing a flexible display, the method comprising:
 providing a plastic substrate having a glass transition temperature from about 350° C. to about 500° C., the plastic substrate comprising a planar surface;   forming a barrier layer to have a major surface, substantially of which contacts the planar surface of the plastic substrate, the barrier layer having a film stress from about −200 MPa to about 200 MPa, the at least one silicon nitride layer having a hydrogen atom content from about 13% to about 17%,   wherein forming the barrier layer comprises alternately stacking at least one silicon oxide layer and at least one silicon nitride layer on the plastic substrate and forming a thin film transistor and an emitting device on the barrier layer.   
     
     
         11 . The method of  claim 10 , wherein the forming of the barrier layer comprises forming the barrier layer using a high temperature deposition technique at a temperature from about 350° C. to about 400° C. 
     
     
         12 . The method of  claim 10 , wherein the barrier layer comprises:
 a first silicon oxide layer;   a silicon nitride layer stacked on the first silicon oxide layer; and   a second silicon oxide layer stacked on the silicon nitride layer.   
     
     
         13 . The method of  claim 10 , wherein the barrier layer comprises:
 a first silicon oxide layer;   a first silicon nitride layer stacked on the first silicon oxide layer;   a second silicon oxide layer stacked on the first silicon nitride layer;   a second silicon nitride layer stacked on the second silicon oxide layer; and   a third silicon oxide layer stacked on the second silicon nitride layer.   
     
     
         14 . The method of  claim 10 , wherein the barrier layer comprises:
 a first silicon oxide layer;   a first silicon nitride layer stacked on the first silicon oxide layer;   a second silicon oxide layer stacked on the first silicon nitride layer;   a second silicon nitride layer stacked on the second silicon oxide layer;   a third silicon oxide layer stacked on the second silicon nitride layer;   a third silicon nitride layer stacked on the third silicon oxide layer;   and a fourth silicon oxide layer stacked on the third silicon nitride layer.   
     
     
         15 . The method of  claim 10 , wherein the at least one silicon oxide layer has compressive film stress, and wherein the at least one silicon nitride layer has tensile film stress. 
     
     
         16 . The method of  claim 10 , wherein a film density of the at least one silicon nitride layer is from about 2.5 g/cm 3  to about 2.7 g/cm 3 .