Apparatus for chemical vapor deposition

An apparatus for chemical vapor deposition, comprising:

• a process chamber configured to demarcate a reaction space;
• a back plate placed above the reaction space and having a gas inlet in a middle thereof;
• a gas diffusion member arranged below and separated from the gas inlet and coupled to the back plate by a first coupling member and configured to diffuse process gas supplied through the gas inlet;
• a shower head placed below and separated from the back plate and the gas diffusion member and having a middle part thereof coupled to the gas diffusion member by a second coupling member and having a plurality of spray holes perforated therein;
• and
• a susceptor arranged below and separated from the shower head and supporting a substrate,
• wherein the gas diffusion member has a plurality of gas guiding holes formed therein such that the process gas supplied through the gas inlet is diffused toward a lower side of the gas diffusion member, the plurality of gas guiding holes vertically penetrating the gas diffusion member;
• wherein the gas diffusion member comprises a support plate;
• and a protrusion member formed on an upper surface of the support plate;
• wherein the gas guiding holes are formed in the protrusion member;
• and
• wherein a ring-shaped diffusion channel connecting bottom parts of the gas guiding holes is formed in the gas diffusion member and a diffusion plate installed on a lower surface of the gas diffusion member so as to cover the diffusion channel, wherein a plurality of diffusion holes off-centered from centers of the gas guiding holes are formed in the diffusion plate.