Strained silicon two-dimensional electron gases on commercially available Si_1-xGe_x relaxed graded buffers

In this work, we describe the growth of two-dimensional electron gas (2DEG) structures in strained Si on commercially available SiGe relaxed graded buffers with 20% Ge fraction. Most work to date on 2DEG's focuses on x=0.3 and above for larger conduction band offsets. In this work we demonstrate the suitability of commercially available relaxed buffers for these structures, for eventual quantum computing applications based on the spin of electrons in Si (1). The use of commercially available buffers is desirable because of their very high quality and because it is often difficult for a single system to grow both the thick buffer and the thin precise layers for 2DEG's. 20% Ge buffers are used because higher Ge fractions are not easily commercially available. The modulation of the electron gases we grow using atomic layer deposited (ALD) Al₂O₃ is also demonstrated. copyright The Electrochemical Society.