SiGe MEMS at processing temperatures below 250 °C

This work demonstrates, for the first time, the use of a post deposition laser annealing technique to realize operational SiGe MEMS devices at deposition temperatures as low as 210 °C. The patterned amorphous SiGe layers are treated by an excimer laser to induce crystallization. After the laser treatment, SiGe devices with good electrical and mechanical properties, such as contact resistivity values to a TiN electrode as low as 4.9 × 10−7 Ω cm2 and a strain gradient of −1.6 × 10−6 μm−1, are obtained. Devices such as an array of functional capacitive test structures and capacitive switches are realized.