Load Stations and Cantilever, Push/puller and Auto Lifter Loading Systems

Load Stations

RCH Associates' load stations are comprised of a structural weldment frame for optimum rigidity. The entire frame and associated paneling are coated with high temperature Urethane.

Load stations may be open clean room frames or they may include HEPA filtering for a particle-free loading bay.

Cantilever-ready load stations include integrated, rigid mounting for drive mechanisms (boat loaders). All surfaces exposed to the substrates are mirror-finished stainless steel for optimum cleanless.

HEPA filtered load stations include a high efficiency overhead light module and are U.S. Federal Standard Class 100.

Drive Mechansims (Boat Loaders)

RCH Associates' drive mechanisms are universally used for both diffusion and LPCVD process cantilevers. They provide smooth, vibration-free motion for moving wafers into and out of process tubes or chambers.

Drive mechanisms are configured for unhindered clean-air flow across the wafers and are comprised of:

• Aluminum strong back with 1mm deflection rating
• Linear bearings for optimum structure and smooth

       operation

• Heavy-duty carriage assembly for mounting of cantilevers
• Ball screw drive
• Intelligent, programmable motor control with self-adjusting torque
• Remote operation by ASTRA Control System or other controller and local (manual) operation
• End-of-travel sensors and over-travel interlocks located for easy adjustment access
• Mirror-finished stainless steel covers sectioned for easy maintenance access

Atmospheric Cantilevers

RCH Associates offers 2 cantilever load beam types:

• Twin-rod - comprised of 2 alumina or silicon carbide rods sheathed in quartz and joined by quartz coupling bars
• High purity silicon carbide paddle

The twin rod design is less costly but, for larger, heavier wafer loads the paddle is recommended. Each is designed for accurate alignment of wafers to the process tube.

Atmospheric Paddle Cantilever

• Rigid and accurate alignment of wafer loads
• Atmospheric oxidation and diffusion process applications
• High purity silicon carbide paddle (semiconductor grade)
• 5-axis alignment with lock downs
• Heavy duty adapter plate for carriage mount to drive mechanism
• Stainless steel scavenger seal plate
• Quartz tube-sealing door
• Dual door support quartz shafts with sleeves
• Finger-tight collet-type clamping of quartz shafts
• Independent door adjustments
• Spring loaded with corrosion resistant springs located outside of scavenger

LPCVD Cantilevers

Similar to atmospheric cantilevers, LPCVD vacuum cantilevers are offered with the 2 types of load beams, twin-rod and paddle.

These cantilevers are designed for high integrity vacuum sealing of LPCVD process chamber flanges.

LPCVD Paddle Cantilever

• Rigid and accurate alignment of wafer loads
• 5-axis paddle alignment system with lock downs
• Heavy-duty adapter plate and carriage mount to drive mechansim
• Vacuum machined 300 Series stainless steel door assembly with silicone o-ring seal
• Stainless steel paddle containment tube with compression vacuum bellows
• High purity silicon carbide paddle with optional CVD coating for etch resistance

Auto Push/puller

RCH Associates offers low cost push/pullers that automatically push and pull wafer boats that are in contact with the process tube wall.

The auto loading mechanism is motor driven and includes an adjustable pull rod clamp.

End-of-travel sensors are provided along with remote operation from the process controller. In addition, the unit may be operated from a local operator panel.

Auto Lifter

The RCH Associates' Auto Lifter is a stand-alone device that is used to lift heavy wafer loads to tube-levels for manual insertion and retraction.

The unit is comprised of a counter-balanced base on casters and a vertical channel member to raise the wafer boat. The wafer boat resides on a horizontal lifting member that is motor driven to raise and lower the load.

A pendant panel contains switches for up and down operation. An onboard motor and position controller sets positions and provides interlocking for safe operation.