Ultra-Thin Free-Standing Single Crystalline Silicon Membranes With Strain Control

TL;DR

This paper presents a method to fabricate ultra-thin, free-standing single crystalline silicon membranes with tunable strain, enabling the study of low-dimensional electronic, photonic, and phononic phenomena.

Contribution

A novel fabrication technique with strain control via a compensating frame for ultra-thin silicon membranes is introduced.

Findings

Strain in silicon membranes can be precisely tuned using the new method.

The membranes' mechanical and band structure properties are controllable.

The membranes serve as platforms for studying low-dimensional phenomena.

Abstract

We report on fabrication and characterization of ultra-thin suspended single crystalline flat silicon membranes with thickness down to 6 nm. We have developed a method to control the strain in the membranes by adding a strain compensating frame on the silicon membrane perimeter to avoid buckling of the released membranes. We show that by changing the properties of the frame the strain of the membrane can be tuned in controlled manner. Consequently, both the mechanical properties and the band structure can be engineered and the resulting membranes provide a unique laboratory to study low-dimensional electronic, photonic and phononic phenomena.