Kla Corporation

Mandar Paranjape

Anatoly Romanovsky

Zhiwei Xu

Steve Yifeng Cui

Yury Yuditsky

Yifeng Cui

Nadine Asenbaum-Doerre

Jeff Chen

Million Daniel

A semiconductor wafer is inspected using a main laser beam and a secondary laser beam. The secondary laser beam leads the main laser beam and has lower power than the main laser beam. Using the secondary laser beam, a particle is detected on the semiconductor wafer having a size that satisfies a threshold. In response to detecting the particle, the power of the main laser beam and the power of the secondary laser beam are reduced. The particle passes through the main laser beam with the main laser beam at reduced power. After the particle has passed through the main laser beam with the main laser beam at the reduced power, the power of the main laser beam and the power of the secondary laser beam are restored in a controlled manner that is slower than a single step.

Large-particle monitoring with laser power control for defect inspection

A laser-beam power-modulation system includes an acousto-optic modulator (AOM) to receive a laser beam and separate the laser beam into a primary beam and a plurality of diffracted beams based on an input signal. The power of the primary beam depends on the input signal. The system also includes a slit to transmit the primary beam and dump the plurality of diffracted beams, a controller to generate a control signal based at least in part on feedback indicative of the power of the primary beam or the power of a beam generated using the primary beam, and a driver to generate the input signal based at least in part on the control signal.

Laser closed power loop with an acousto-optic modulator for power modulation

Growing community of inventors

Cupertino, CA, United States of America

Mandar Paranjape