CVD Equipment Corporation's Series 6000 Furnace Systems are offered for diffusion, oxidation, annealing and low pressure chemical vapor deposition (LPCVD). Our standard and custom systems provide the best possible choice for your wafer fabrication needs.

• Single and multi-wafer systems.
• Single and multi-tube systems.
• Standard 1 through 4 stack platform with right or left-hand loading.
• Cluster tool platform for single or batch wafer processing. Cluster tool platform transfers wafer(s) under high vacuum between process tubes. This allows for the growth of ultra thin oxide layers or prevents the growth of an oxide layer when transferring wafers between process tubes.
• Atmospheric, LPCVD and UHVCVD processing capability.

Available Furnace Systems Features Include:
• Processing of wafers up to 300 mm in diameter
• Operational temperature from 100 to >1300 degrees Celsius
• Closed tube processing for high purity and a reproducible environment resulting in increased production yields
• Moving furnace element for fast heat-up, cool down and to insure a proper process atmosphere exists prior to processing
• Cantilever Loading System for automatic, noncontact loading of the wafer boat for minimal particle generation.
• Cascade temperature control using external (furnace) and internal (process) thermocouples for real time continuous in situ control of temperature profile
• Better than 1/2 degree Celsius flat zones up to 48" in length
• Independent computer control of each process tube
• 1 through 4 stack systems available with right or left hand load stations

Diffusion and Oxidation
Our closed tube systems and proprietary quartzware designs offer many benefits over the more standard open tube designs. Some of the benefits are:
• No scavenger exhaust -- gases are exhausted in a well defined manner thereby reducing corrosion, cleanroom contamination and improving operator safety
• Process results are independent of scavenger exhaust
• No back diffusion of air while processing
• Improved temperature uniformity
• Reduced energy consumption
• Reduced process gas consumption
• Improved deposition uniformity and quality
• When coupled with our moving furnace design, a positive control of the wafer atmosphere is assured at all times

Systems are offered with automatic gas controls for Wet/Dry Oxidation, Pyrogenic Oxidation, Liquid Source Doping and Gaseous Source Doping.


Annealing Furnaces for Gallium Arsenide, Silicon, Germanium

All semiconductor material that has had its crystalline structure changed in some way should be annealed. For example, during ion implantation, the ions transfer some of their momentum to the wafer lattice, damaging it in the process. Ion implantation followed by a furnace anneal in which enough thermal energy is imparted to the atoms allows them to rearrange themselves into a crystalline array. To prevent decomposition of the wafer material during annealing, an over- pressure of the volatile component is often used. Annealing atmospheres of Hydrogen, Arsine, Ammonia, Forming Gas, Argon and many others are offered. In Gallium Arsenide, an Arsenic overpressure is used to allow for capless annealing, yielding sheet resistance uniformities after annealing of <2% across the wafer. Annealing is also used for metallization anneals, improving surface state conditions and reducing the resistance of poly-silicon interconnects and forming silicides.


Low Pressure Chemical Vapor Deposition (LPCVD) for Polysilicon, Silicon Dioxide and Silicon Nitride

Our innovative designs for heating, temperature control, quartzware and gas injection result in better uniformity and yield than conventional systems. Our ease of system access for maintenance or repair results in less down time. Overall, the system gives higher productivity and a lower cost of ownership. System features include:

• The heating element we use is specifically designed for applications requiring precision uniform heating in both the radial and axial directions. The sinuated heating element coil design is superior over the larger diameter Helix (spiral) type designs commonly found in most Diffusion Furnaces. The large diameter designs are unable to provide the uniform temperature requirements required for LPCVD. This inability is due to the large area spacing between the Helix windings which cover less of the heating surface area, and the inability of the heating element with its exposed windings to act as a black body to uniformly radiate throughout the heating area. The heating element we use has a much finer heating coil with a sinuated design, that covers a greater surface area and is completely embedded within the insulation and overcoated 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.

• To further improve temperature uniformity, our evacuated, quartz wool filled Thermal Plug minimizes heat loss from the loading end of the system. This allows our heating elements to achieve better flat zone temperature specifications in a shorter distance. The thermal plug coupled with our unique gas injectors, minimizes deposits at the loading end of the system and pre-reaction of the gases. As an added benefit, power consumption is reduced.

• Our cascade temperature control system allows for direct control of process temperature from thermocouples located directly beneath the wafer load. Having direct control by the internal thermocouples, enables the user to change process conditions, pressure, flowrate, gas compositions, wafer load and operating temperature without having to re-profile the heating element.