Method of defining poly-silicon growth direction

A method of defining poly-silicon growth direction, comprising steps of:

• step 1, providing a glass substrate and cleaning the glass substrate;
• step 2, forming a buffer layer on the glass substrate;
• step 3, forming a metal film layer on the buffer layer;
• step 4, implementing etching to the metal film layer with an acid liquid to form a metal film array;
• step 5, covering an area of the buffer layer outside the metal film array with a high-purity quartz mask to expose the metal film array;
• step 6, forming a graphene layer on the high-purity quartz mask and the metal film array;
• step 7, implementing etching to the graphene layer to form a graphene layer array coinciding with the metal film array of the fourth step;
• step 8, forming an amorphous silicon thin film on the buffer layer having the metal film array and the graphene layer array;
• step 9, implementing high temperature dehydrogenation to the amorphous silicon thin film;
• step 10, implementing an Excimer laser anneal process to the amorphous silicon thin film, and the amorphous silicon thin film melts after absorbing the energy of the laser and temperature rising;
• step 11, melted amorphous silicon is re-crystallized and starts growing and becomes larger from a low temperature area comprising the metal film array and the graphene layer array toward high temperature areas around to form poly-silicon;
• wherein the buffer layer in the second step comprises two portions, one portion near the glass substrate is amorphous silicon nitride SiNx, and the other portion relatively far from the glass substrate is silicon oxide SiOx, and the SiOx is on the SiNx;
• wherein the metal film layer in the third step is formed by physical vapor deposition metal coating;
• wherein a thickness of the metal film layer in the third step is 10-500 nm;
• wherein a material of the metal film layer is one or more of copper Cu, nickel Ni, gold Au, platinum Pt, iron Fe, molybdenum Mo, aluminum Al, and the purity≧99.9%;
• wherein in the sixth step, a thickness of the graphene layer is 0.35-20 nm;
• wherein in the sixth step, the graphene layer is formed by low-temp chemical vapor deposition graphene coating with hydrocarbons as a source of carbon;
• wherein process conditions of the chemical vapor deposition are:
• the pressure is 5 Pa-5 kPa, and the temperature is 400-680 degrees Celsius;
• wherein in the seventh step, the etching to the graphene layer is implemented by laser etching or dry etching;
• wherein the positions of the metal film array and the graphene layer array are located near a channel.