Chemical Vapor Deposition

Types of CVD	Properties	Advantages	Disadvantages
APCVD	- 76~760 Torr - Chemical raction by thermal energy - Used in SiO2 deposition - Coldwall Reactor	- Low temperature - Simple reactor - Fast Deposition Rate (70nm/min)	- Poor step coverage - 다량의 Carrier gas waste - Particle Contamination - Low throughput (cause of wafer loading) - Frequent Cleaning Required
LPCVD	- Low pressure (0.25~2Torr) - 10~50nm/min - SiO2, Poly Si, W, Si3N4 Deposition - Hot-wall reactor (for prcise control) - Low gas pressure (no carrier gas)	- Large wafer capacity - High Uniformity - Good Step Coverage - Low cost (because of batch process)	- Sensitive Rate Control (sensitive to temperature) - High Temperature (500~1200C)
PECVD	- Energy supplied by plasma - Low temperature (300~400C) - Nitride passivation layer deposition(고온공정 불가능한 경우 사용)	- High deposition rate (than LPCVD) - Low pinhole density (good film density) - Good Step Coverage	- Particle&Chemical Contamination - Low Uniformity - 조성비가 좋지 않음
MOCVD	- Metal-organic precursor 사용 - decomposition at low temperature - compound semiconductor의 경우 MOCVD 사용	- Growth Rate Control - Good Step Coverage - Low defects	-Toxic, Explosive Gas
CVD vs PVD	CVD is the process that deposits film through chemical reaction and surface adsorption without changing the substrate properties	- Higher growth rate possible - Can deposit materials hard to evaporate (poly Si, SiO2, Si3N4, ....) - can grow epitaxial film - more conformal step coverage + uniformity	- Higher temperature - Complex process - Toxic, Corrosive Has