Multilayer microheater based on glass substrate using MEMS technology

A microheater with a multilayer structure on a glass substrate is designed and fabricated using microelectro-mechanical systems (MEMS) technology. The micro-hot plate mainly comprises a glass substrate, two silicon nitride layers, a silicon oxide layer, a multilayer heater, and two electrode pads. In general, platinum, being a noble metal, does not adhere well to materials like silicon nitride or dioxide. To improve the problem, a multilayer structure was performed to enhance the thermal adhesion stability of thin platinum film. The multilayer heater is consisted of chromium (Cr), chromium nitride (CrN), platinum (Pt), chromium nitride (CrN), and chromium (Cr). The Cr and CrN are used as the intermediate materials between the Pt and the silicon oxide in order to improve adhesion. The couples of Cr-CrN and CrN-Pt have good thermal stress resistance due to their similar thermal expansion coefficients. Results showed that the multilayer heater could improve structure adhesion and decrease degradation for stability and reliability. The microheater can be heated up to about 498 degrees C with about 22 degrees C fluctuation corresponding to a power consumption of about 2.35 W. For duration test, the microheater operates without damage at a heating temperature of 496.5 degrees C for 72 h. (C) 2015 Elsevier B.V. All rights reserved.