Method for forming polycrystalline silicon film

• Main Authors: LEE JUN HO, LEE HO NYEON, PARK JAE C, KIM EOK S, SON KYOUNG SEOK, RYU MYUNG K, KWON SE Y
• Format: Patent
• Language: English
• Published: 30.06.2005
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; SEMICONDUCTOR DEVICES; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

Disclosed herein is a method for forming a polycrystalline (poly-Si) film by the crystallization of an amorphous silicon film using laser light irradiation. The disclosed method comprises the steps of: sequentially depositing a buffer film and an amorphous silicon film on a glass substrate; depositing a metal film having laser light reflection function on the back side of the glass substrate; and irradiating the front side of the amorphous silicon film with laser light to crystallize the amorphous silicon film. In the laser light irradiation step, the irradiated laser light is absorbed into the amorphous silicon film, and a portion of the absorbed laser light is transmitted through the amorphous silicon film. The transmitted light is reflected from the metal film and absorbed into the amorphous silicon film again, thus crystallizing the amorphous silicon film twice over. According to the present invention, the amorphous silicon film is crystallized twice over so that a polycrystalline film having very large grains can be formed.