Ultra-High Vacuum Multi-Chamber Cluster Tool (UHVCVD)

CVD Equipment provides batch processing for single or multi-tube low temperature epitaxial (LTE) deposition systems for Silicon (Si) and Silicon Germanium (SiGe) layers with 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.

UHVCVD System Features Include:

• Ultra High Vacuum
• Deposition within a high purity, double walled quartz process tube.
• Cantilevered Non-Contact Automatic Loading System prevents particle generation and promotes long term processing without having to change the quartz process tube.
• Ultra High Vacuum Loadlock maintains the process tube in a clean process atmosphere at all times.
• Multi-Wafer batch processing uses standard quartz wafer boats.
• All Metal Sealed gas control system is clean, leak tight and interfaced with the microprocessor control system for automatic or manual operation. The gas flow control system incorporates:
• Metal sealed mass flow controllers
• Nupro air-operated diaphragm valves
• 316L stainless steel lines
• Cajon VCR fittings.
  
• Prior to final assembly, the tubing is cleaned and passivated to eliminate any possible contaminants.
• Upon completion, the system is Helium leak checked to a level of 1x10E-9 Atm. ss/sec.
• Built in Residual Analyzer (RGA).
• Precision Multi-Zone Furnace Temperature Control System provides for better than +/-.25 degrees Celsius control. Temperature is digitally set and displayed in .1 degree Celsius increments.
• Furnace Heating Element is specifically designed for low temperature processing. The heating element uses a fine sinuated heating coil which covers a greater surface area and is completely embedded within the insulation, and over coated so that there is no direct radiation from the heating coil. The inside of the heating element is then blackened to make the unit act as a black body radiator - the most uniform method of heating available.

Utilizing IBM's patented methods developed for Low Temperature, Low Pressure Chemical Vapor Deposition of Silicon-Germanium Epitaxial layers, our production proven multi-wafer systems offer unique advantages for precision control of film thickness, composition and concentration profiles.

SiGe based ICs operate at speeds previously thought to be beyond the reach of silicon technology and are becoming the first real challenge to in high-volume, high-speed telecommunications and wireless applications. The benefit of this technology is its reduced cost and improved manufacturability. Cost reduction results from the compatible manufacturing of Silicon Germanium with high volume silicon based CMOS fabs and the productivity improvement of processing larger wafers.

Layer Uniformity - within a wafer and wafer-to-wafer within a run is achieved by operating in the molecular flow regime (10E-3 Torr) where complex hydrodynamic effects are absent and silane gas phase decomposition is suppressed. The constant temperature and uniform flat zone created by the resistance heating element assures reproducible batch processing results from run-to-run.

Layer Quality - is assured by the use of a hot, double walled quartz growth chamber whose internal surface is continually coated with the same material as deposited on the wafer surface. This ideal growth environment is maintained from run-to-run by the ultra high vacuum system.

Layer Composition - is assured because low temperature deposition prevents desorption of previously deposited species or the diffusing of new species into the deposited layers.  This allows multi-layer deposits with no effect on the doping patterns of the underlying or new layers.

Unsurpassed Performance

Cost Per Wafer - is measured by more than the initial cost of the system installed on your production floor.  Wafer throughput per month, yield, system uptime, automatic operation, maintenance downtime and consumables are other factors which significantly affect the overhead cost per processed wafer. On all of these counts, the UHV system is unsurpassed in performance.

Wafer Throughput - unlike single wafer processing systems, the UHVCVD is a batch processing system capable of processing 20 plus wafers per run for all common wafer diameters.

Yield - is a function of layer quality, wafer-to-wafer uniformity and run-to-run reproducibility. The production proven UHVCVD system design with automated controls ensures superior yields.

System Up-Time - the use of production proven reliable components ensures high system availability. High purity automatic gas controls feature 316L stainless steel orbital welded gas lines, Cajon VCR connections, metal sealed mass flow controllers, sub-micron filtration and air-operated diaphragm valves.

Automatic Operation - the UHVCVD is controlled by a user friendly microprocessor control system that ensures run-to-run repeatability with minimal operator assistance. After the wafer boat is loaded into the process tube, the operator only needs to start the appropriate deposition program. The PC-based microprocessor control system automatically executes the program sequence generating the gas flow, temperature and vacuum profiles required for a specific film deposition. It also sequences valves, vacuum pumps and, on a real-time basis, monitors all gas flows, pressures, temperatures and safeties. Logging of run data-to-disk and hard copy printout are provided.

Maintenance Downtime - is minimized throughout the system. From dry-vacuum pumping to cantilevered non-contact automatic loading, we provide a system where routine weekly or monthly maintenance has been virtually eliminated. System design and construction promotes long-term processing, even in the changing of the quartz process tubes.

Consumables - there are no susceptors to change or quartzware to clean on a regular basis.