Profilometry Based on Heterodyne Interferometry with Nanometer Sensitivity

摘要

Optical profilometry enables new dimensions of sensitivity in order to detect surface properties such as roughness and planeness of reflecting materials. For this purpose we developed an optical profilometer based on high-sensitivity heterodyne interferometry where a measurement beam is scanned over the surface of the device under test (DUT). With this measurement setup we are able to measure surfaces with approximately 5 nanometer accuracy. For scanning we developed a beam actuation system and a DUT actuation system with a lateral sensitivity of about 15μm.