Low drift scanning probe microscope

摘要

A scanning probe microscope, such as an atomic force microscope, include a z-stage and a bridge structure comprised substantially free of Invar. A scanner containing a probe is mounted to the z-stage, which is movable in the z-axis to raise and lower the probe. A drift compensation system is provided to reduce thermal drift of the z-stage and the bridge. The drift compensation system includes heating elements thermally coupled to the z-stage and the bridge, ambient temperature sensors, and a controller to actively control the heating elements to maintain the bridge and the z-stage at an elevated temperature.

主权项

1. An atomic force microscope comprising:
a base; a bridge structure coupled to and supported by the base, the bridge structure substantially free of Invar®; a z-axis actuator coupled to the bridge structure; a head assembly coupled to the z-axis actuator, the head assembly including an atomic force probe; a platform for supporting a sample to be scanned generally below the head assembly; a heating element coupled to the bridge structure; a temperature sensor operative to measure a temperature of the bridge structure; a thermal controller operative to receive signals from the temperature sensor containing information regarding the temperature of the bridge structure, and further operative to control the heating element to heat the bridge structure to maintain the temperature of the bridge structure at a relatively constant temperature during scanning of the sample; and further comprising another heating element coupled to the z-axis actuator and another temperature sensor operative to measure a temperature of the z-axis actuator, and wherein the thermal controller is further operative to receive signals from the second mentioned temperature sensor regarding the temperature of the z-axis actuator and operative to control the second mentioned heating element to heat the z-axis actuator to maintain the temperature of the z-axis actuator at a relative constant temperature during scanning of the sample.