Patent ID: 8355624

Claim:
A heat treatment apparatus for exposing a substrate to light to heat the substrate, comprising: a chamber for receiving a substrate therein; a susceptor having a frontside surface and a backside surface for holding the substrate on the frontside surface thereof within said chamber, said susceptor being formed of a transparent material, wherein only a region of the backside surface of said susceptor reached by light emitted from the light source and passing by the substrate held by said susceptor into said susceptor has a rough surface, and a light source for emitting light to expose the substrate held by said susceptor to the light, wherein the rough surface of the backside surface of the susceptor is of a degree of roughness such that light passing by a peripheral portion of the substrate during heat treatment of the substrate is diffusely reflected from the backside surface, with part of the diffusely reflected light impinging on the peripheral portion of the substrate.