Berkeley Process Control, Inc.

Sanjay K Aggarwal

Nathan H Harding

Paul Sagues

Robert T Wiggers

Kevin D D'Souza

A wafer handling apparatus having input and output robotic systems directed by a programmed controller. Each system has components including a robot, a twist and rotate, and a carrier and automated carrier rail. The input system is for removing wafers from their wafer pod, placing them in the carrier and transporting them via the rail to a wafer processing area. The output system performs the reverse operation, taking wafers from a carrier following processing and placing them in a pod. Each robot includes a plurality of interconnected, articulated cantilevered arms. The last one of the arms has a wand on one end and a laser emitter detector on the other end, and operates in cooperation with the controller to provide location detection of system components. The controller also includes circuitry for sensing contact of the wand with an object by measuring the increased robot motor torque occurring upon contact. The controller is pre-programmed with approximate physical dimensions of the system components and their relative positions. The controller is additionally programmed to automatically perform a precision calibration/teaching routine to gather more precise location data. The process of precision teaching/calibration begins by placing a pod calibration fixture on a pedestal. The controller then directs the input robot to sense the fixture position, which gives the controller precise data relating to the position of a pod on the pedestal. The robot then senses the position of the twist and rotate components. The process begins by sensing the height of two arms of the twist and rotate, and the controller adjusts the arm heights until they are level. The controller then directs the robot to sense the R and &thgr; dimensions of the twist and rotate, and these precise dimensions are saved in the controller.

Self teaching robotic wafer handling system

Briefly, a preferred embodiment of the present invention includes a wafer carrier buffer for storage of a plurality of carriers containing wafers either waiting to be taken for processing in an adjacent wafer processing system, or waiting to be taken from the buffer following the processing. The buffer has a sliding carrier first input apparatus for taking a carrier from outside the buffer through a buffer input door and into the buffer interior. A buffer controller is included for directing robotic apparatus to take the carrier from the input apparatus and place it on a selected one of a plurality of carrier storage locations, and from a carrier storage location to a first output for delivery of wafers to processing. The robotic apparatus also delivers an empty carrier to a second input apparatus for receiving wafers from the processing area, and for delivery of a carrier with processed wafers to a second sliding output apparatus for removal from the buffer through a buffer output door. The controller is programmed to direct an automatic calibration of all of the carrier storage locations and the input and output positions. The robotic apparatus includes a sensor for detecting the position of a flange on a calibration fixture that is placed by the robot at a carrier storage location. The flange is accurately positioned on the fixture to correspond to a similar flange on each carrier that is used to engage with a tool on the robotic apparatus for moving the carrier. The calibration is preferably done by directing the robotic apparatus to place the calibration fixture at a location in need of calibration and then sensing the precise position of the fixture flange with the sensor apparatus. The controller then calculates the coordinates required to place a carrier accurately in that location. This process is repeated for each carrier storage location and the input and output locations.

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Berkeley, CA, United States of America

Sanjay K Aggarwal