POLYCRYSTALLINE THIN FILM FORMING METHOD AND THIN FILM SEMICONDUCTOR ELEMENT

摘要

PURPOSE: To provide the method with which the crystal uniformity of the polycrystalline thin film on a substrate can be improved, and the irregularity in efficiency of the device arranged on the surface of the substrate is suppressed using the annealing of laser beam. CONSTITUTION: A microscopic crystal Si thin film, having the average crystal grain diameter of about 20nm or smaller, is formed by annealing the amorphous Si thin film 2 on a substrate 5 using an excimer laser beam 1 in the first step of annealing, and a polycrystalline Si thin film 4 is formed by annealing the microscopic crystal Si thin film 3 using an excimer laser beam 1 in the second step of annealing. A thin film transistor is formed using the above-mentioned polycrystalline Si thin film 4.