SCREAM I: A single mask, single-crystal silicon process for microelectromechanical structures

A process outline for a one-mask version of the single-crystal silicon reactive etch and metal (SCREAM) process called SCREAM-I, for fabricating silicon microelectromechanical (MEM) devices, is presented. The process defines single-crystal silicon (SCS) high-aspect ratio beams using submicron optical lithography. The process defines MEM devices with a single mask, including contact pads, interconnects, released beams, and lateral capacitors. SCREAM 1 is a self-aligned, low-temperature (<300°C) process that can be completed in ≈6-8 hr. All fabrication steps rely on industry standard, high-throughput fabrication tools. Beam elements 0.5 μm to 5 μm in width can be fabricated with aspect ratios of greater than 10 to 1