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).
"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: Vol. 4
, Article 17.
Available at: http://scholarworks.uark.edu/inquiry/vol4/iss1/17