Design Philosophy
The system described herein is a RF or Microwave Plasma CVD (Chemical Vapor Deposition) System. The system is capable of producing single crystal and polycrystalline films for research and production. The substrate stage is made of refractory metal and is heated inductively by 100 KHz induction heater and matching network. Temperatures up to 1400º C can be achieved. The system is fully computer controlled.
In addition to the automated sequence control, the system can be operated manually. This can be useful in determining information such as the approximate flow rates to reach a desired pressure. A process can be run on the deposition control software by the user, however, the power supply enable(s) and shutters must be manually selected when they are required. A special Service Mode is available which allows manual operation of any control regardless of the state of the tool. This Service Mode is useful for repairs, maintenance and regular servicing of the system.
Data logging of tool parameters (e.g., flows, pressure, temperature, actual source values) to a selected file can be enabled by the user at any time. This allows not only data from a run to be recorded, but also information from a pump down to assist in verifying the correct operation of the tool. The deposition control software also has data logging capability to capture process related information.
Specifications 1.Process Chamber- water cooled 14” diameter x 12” height electro polished stainless
steel, with a 2” diameter view port on the front; a top-opening access door for wafer
loading, cleaning and maintenance. The access door is equipped with a pneumatic hoist.
2.Vacuum Pumping- is a mechanical pump Fomblin propped, about 40 cubic meter/hour
with an ultimate vacuum of 10-4Torr.
3.Vacuum Gauging- A capacitance manometer (10 Torr range) for process pressure
monitoring and control with front panel digital read-outs and another capacitance
manometer measure pressure from atmosphere to 1 Torr.
4.Gas Delivery Control- will be through 6 Mass Flow Controllers with shut off valves for Silane, Argon, Nitrogen, Methane, Hydrogen (100-200- sccm), or/and other gas and a water cooled gas shower over the wafer stage to achieve good uniformity of deposition. Other gases may be used if the required gas correction factor is used for detecting mass flow of that certain gas. The gas delivery is done through stainless steel coaxial lines with the corrosive gases in the center line and the outer line at a lower pressure so any leak of dangerous gases will remain in outer line and will be detected by gas detectors provided. All mass flow controllers will be placed inside a sealed gas box whose pressure is maintained a few inches lower than the atmospheric pressure.
5. Wafer/Sample Stage-9” dia Molybdenum substrate stage with induction heating through
a water cooled induction coil and temperature control by a pyrometer & monitoring,
capable of mounting up to two 4” wafers or a number of wafers of smaller diameter, with
a size-matched insulated toelectrode.
6. RF Power Supply-2KW, 13.56 MHz air-cooled solid state, fully protected state-of-the-art power supply with auto matching network with display of forward and reflected power. A microwave power supply, 2.4 GHz is given as an option.
7. Type of Deposited Film – With the gases used it will be possible to deposit single crystal, or polycrystalline films such as silicon dioxide (Si02), Silicon Nitride (SiN4), amorphous silicon, silicon oxy nitride, silicon Nitride (SiN) etc.
8. Thickness of Thin Film – Thickness from a few microns up to 10 mm or more is possible. Uniformity is better than 3%.
9.
UTILITIES:
COMPRESSED AIR @60-70 psig
INPUT POWER 220-240V, 50Hz, 20 amps
The whole system is integrated, interlocked for safety. All displays of operating parameters will be conveniently located on the front control console. The whole system will be mounted on convenient stand and is compatible with CLEAN ROOM operation.
