Process Description

Low Pressure Chemical Vapor Deposition is a process that uses a chemical reaction to convert gas phase precursors or chemicals into useful films. The products of that reaction are deposited on top of the wafer and will therefore not consume atoms from the base material. LPCVD processes are often used in the semiconductor industry to produce high purity / high quality thin films.

Process Parameters

• Reactor chamber pressure (100 to 250 mTorr).

• Reactor chamber temperature (550 to 850 oC).

• Gas flowrate.

3 horizontal LPCVD furnaces Tempress Systems model TS 8603. Capable for max. 200 mm wafers, handling of (small) parts is also possible. Heating element 5 zones. Maximum temperature elements 1100° C. 500 – 600oC: ± 1.0oC 600 – 1050oC: ± 0.5oC Thermal flat zone 550 – 600 mm.
1 Vertical LPCVD furnace Tempress Systems, model SBVF (Small Batch Vertical Furnace). Capable for max. 200 mm wafers. Heating element 3 zones. Maximum temperature elements 900° C. 400 – 900oC: ± 0.5oC Thermal flat zone 350 mm, (400 – 900oC)

Types of LPCVD processes

Flat poly
Ramped poly
Amorphous silicon
Phosphor-doped poly-silicon
SIPOS
Stoichiometric nitride
Low stress Nitride
TEOS undoped

Process characteristics

Good dielectric properties of deposited films.
High throughput (batch process)
Uniform and reproducible process.
Good step coverage.