Si/SiGe Epitaxial Equipment

Epitaxial film can be made by APCVD, LPCVD and UHVCVD. In general, the lower the pressure, the lower the growth temperature and growth rate. The choice of the method depends on the application and desired film properties.

We provide multiple solutions for epitaxial film growth for research and production.

APCVD/LPCVD
Si epitaxial and Silicon on an Insulator (SOI) can be made by both APCVD and LPCVD. APCVD operates at atmospheric pressure or slightly reduced pressure. The deposition is done at a high temperature and provides high growth rate. LPCVD operates at below 100 torr range. It offers better uniformity and step coverage than APCVD.

Depending on the precursors used, the system can have a resistance heater, infrared (IR) heater or RF heater.
Precursors used for Si Epi are:

• SiH4: deposition temperature > 850 °C
• SiH2CL2 (dichloride Silane or DCS): deposition temperature > 1000 °C
• SiHCl3 (Trichloride Silane, TCS): deposition temperature > 1100 °C
• SiCl4 (Silicon Tetrachloride): deposition temperature > 1200 °C

SiGe is typical made by LPCVD with an IR furnace or UHVCVD with a resistance furnace.

UHVCVD
UHVCVD operates at a pressure range from 10 mtorr to below 5 torr. The chamber is pumped down to 10E-9 torr before deposition. The UHVCVD lower pressure makes the system have a lower Oxygen content. The system is also kept in the UHV condition when not running to improve cleanliness. A resistance furnace is used for UHVCVD. The hot wall tube also gets a coating of Silicon on it to improve the Oxygen level. A double wall quartz tube is used, which is evacuated between the inner and outer tube to prevent any metal particulates coming off the furnace from diffusing thru the quartz and generating contamination.

The Ultra High Purity condition allows for deposition at a lower temperature (Si 500-700 °C, SiGe 450-650 °C). UHVCVD low temperature epitaxial (LTE) deposition system for silicon (Si) and Silicon-Germanium (SiGe) layers offers outstanding advantages in controlling film thickness, composition and concentration profiles. Operation at low temperature in the molecular flow regime enables the system to produce uniform, ultra-high purity layers having abrupt alloy and dopant profiles with a wide dynamic range.

CVD Equipment offers single chamber UHVCVD systems and cluster systems with both LPCVD and UHVCVD. It is clearly the best choice for SiGe research and production.

Please contact us for further details.