In this study, nanoindentations were produced and characterized for the future patterning of quantum dots. Nanoindentation was performed on a Si-doped (n-type) Vertical Gradient Freeze (VGF) GaAs (100) wafer with a 700 nm GaAs (100) layer grown by molecular beam epitaxy (MBE). Nanoindentation was performed with a Berkovich diamond tip, a cube corner diamond tip, and a 600 conical diamond tip. Nanoindentation of GaAs has been studied in the past, but not at extremely low loads. Previous research has been done on high load (50-200 mN) and low load (200-8000 mN) nanoindentation. The applied load in this study ranges from 400 mN all the way down to 5 mN. The motivation for achieving such low loads is to produce nanoindentations on the same size range as quantum dots (~10-100 nm in width). The smallest indentations achieved were less than 60 nm in width and less than 2 nm deep with the cube corner indenter. The geometry of the indents is characterized using atomic force microscopy (AFM).
Prince, R. (2003). Study of Nanoidentation and Tip Geometry in GAAS (100) at Ultra-Low-Loads for the Patterning of Quantum Dots. Inquiry: The University of Arkansas Undergraduate Research Journal, 4(1). Retrieved from https://scholarworks.uark.edu/inquiry/vol4/iss1/17