APPARATUS AND METHOD FOR DETERMINING CLAMPING STATUS OF SEMICONDUCTOR WAFER

摘要

An apparatus determines how well a semiconductor wafer (4) is clamped to a support member (1). The apparatus has at least one ultrasonic transducer (2a,2b,2c,2d) configured to emit ultrasonic energy (3) toward an interface between the wafer (4) and the support member (1) so that the interface generates echo signals, and a data processing unit (11) configured to analyze the echo signals to arrive at a determination as to how well the semiconductor wafer (4) is clamped to the support member (1) before semiconductor process is started. A first method ensures that a wafer (4) is securely clamped to a support member before a semiconductor process is started.A second method verifies proper de-clamping of a semiconductor wafer (4) from a support member (1) before the semiconductor wafer (4) is removed from the support member (1) upon completion of a semiconductor process.