Method of forming the buffer layer in the LTPS products
The present disclosure disclosed a method of forming the buffer layer in the LTPS products. The method comprises the following steps: heating the substrate to make the alkali metal ions diffuse to the surface of the glass; washing the substrate by acid to remove the alkali metal ions on the surface of the glass; forming the buffer layer on the glass which has been heated and washed by acid, wherein the material of the buffer layer is SiOx. The method of the present disclosure based on the design of the single buffer layer, it can greatly promote the capacity and can economize the gas. Furthermore, it can avoid the cross contamination of the different layers so as to promote characteristic of the element.
1. A method of forming a buffer layer in a LTPS product, comprising:
(a) providing a LTPS product comprising a substrate made with transparent glass or transparent quartz, and having alkali metal ions therein;
(b) diffusing the alkali metal ions to a surface of the substrate;
(c) eliminating the alkali metal ions on the surface of the substrate; and
(d) forming the buffer layer on the substrate.
2. The method as claimed in claim 1 , wherein the step of diffusing the alkali metal ions is operated by oven heating, rapid thermal annealing, or chamber heating to heat the substrate.
3. The method as claimed in claim 2 , wherein temperature range in the step of heating the substrate is from 580° C. to 700° C.
4. The method as claimed in claim 1 , wherein an acid with low concentration is used to eliminate K ions and Na ions on the surface of the substrate.
5. The method as claimed in claim 4 , wherein the concentration of the acid is more than or equal to 4 ppm.
6. The method as claimed in claim 4 , wherein the acid is selected from the group consisting of acetic acid, phosphoric acid and carbonic acid to pickle the substrate.
7. The method as claimed in claim 1 , further comprising:
an initial clean step before the step of diffusing the alkali metal ions; and
another clean step to the substrate after the step of eliminating the alkali metal ions on the surface of the substrate, which is for removing remaining pickling solution.
8. The method as claimed in claim 1 , further comprising:
annealing the buffer layer to optimize the quality of the buffer layer.
9. The method as claimed in claim 1 , wherein the buffer layer is a single layer structure, which comprises SiOx without SiNx.