Textured silicon substrate and method
View Patent ↗A method of texturizing a silicon substrate comprising a) contacting the substrate with an etching solution comprising glycolic acid, b) etching a surface of the substrate thereby forming disruptions in said surface of the substrate, and c) removing the etching solution to yield a texturized substrate, said texturized substrate having a plurality of disruptions in at least one surface with a surface density of disruptions of a minimum of 60 disruptions in a 400 micron square area.
1. A method of texturizing a silicon substrate comprising a) contacting the substrate with an acidic etching solution consisting of hydrofluoric acid, nitric acid, water, and about 4% to about 40% by weight of glycolic acid, b) etching a surface of the substrate thereby forming disruptions in said surface of the substrate, and c) removing the etching solution to yield a texturized substrate.
2. The method of claim 1 wherein the etching solution contains a minimum of 5% by weight of glycolic acid.
3. The method of claim 1 wherein the etching solution contains from about 5% to 28.6% by weight glycolic acid.
4. The method of claim 1 further comprising washing the texturized substrate surface with water or a basic solution, and drying.
5. The method of claim 1 wherein the contacting is by immersing the substrate into the etching solution or by spraying the etching solution onto the substrate.
6. The method of claim 1 wherein the etching rate is from about 0.6 to about 1.3 micrometers per minute.
7. The method of claim 1 wherein the etching rate is kept constant during etching.
8. The method of claim 1 wherein the etching solution consists of on a weight percent basis from about 37.4% to about 39.2% hydrofluoric acid from about 16.0% to about 16.8% nitric acid from about 37.4% to about 39.2% water, and from about 4.8% to about 9.1% glycolic acid.
9. The method of claim 1 wherein the etching solution consists of on a weight percent basis from about 38.9% to about 42.4% hydrofluoric acid, from about 16.7% to about 18.2% nitric acid, from about 27.8% to about 30.3% water, and from about 9.1% to about 16.7% glycolic acid.
10. The method of claim 1 wherein the etching solution consists of on a weight percent basis from about 21.0% to about 26.7% hydrofluoric acid from about 21.0% to about 26.7% nitric acid, from about 29.4% to about 37.4% water, and from about 9.1% to about 28.6% glycolic acid.
11. The method of claim 1 wherein the etching solution consists of on a weight percent basis from about 23.9% to about 25.1% hydrofluoric acid, from about 23.9% to about 25.1% nitric acid, from about 43.1% to about 45.1% water, and from about 4.8% to about 9.1% glycolic acid.