Multiple Heaters in a MEMS Device for Drift-Free HREM with High Temperature Changes

摘要

The use of MEMS-based micro heaters for heating experiments in electron microscopy is known. Heating of a sample typically relates to a temperature increase or decrease of at least 50 K, and often at least 200 K. The present invention provides an improved heating system for use in an observation tool requiring low drift of 0.2 nm/sec, such as an electron microscope, comprising two cooperating and integrated MEMS-based micro heaters (21,22) spaced apart at a mutual distance of less than 10 mm. A first heater is a master heater (21) and capable of receiving a first amount of power, a second heater is a slave heater (22) and capable of receiving a second amount of power, wherein the first and second amounts of power are in a range from 0 mW to the total amount of power. A thermometer is measuring the temperature of the master heater in use with an accuracy of better than ±10 mK, and a power controller prevents variation in the total amount of power received by keeping the total amount of power constant with an accuracy of better than ±5 pW and divides the total amount of power over the at least two heaters.