A scanning tunneling microscopy study of As/Ge(mnn) and P/Ge(mnn) surfaces

Abstract

Ge(mnn) surfaces between (100) and (111) were annealed under either arsine or phosphine in a metal-organic chemical vapor deposition chamber, then imaged with a scanning tunneling microscope. In general, arsine-exposed Ge surfaces are facetted, while phosphine-exposed surfaces remain flat. For the arsine-exposed Ge surfaces, four stable facetting directions have been identified: (100), (11,3,3), (955), and (111).

An RDS, LEED, and STM Study of MOCVD-Prepared Si(100) surfaces

“…This etching is attributed to a reaction of the form 3Si(s)+4AsH 3 (v) -4 As 4 (v)+3SiH 4 (v), which cannot occur for Si samples annealed under As 4 . AsH 3 has also been observed to etch Ge, though not so dramatically [9]. In general, this sort of roughening is undesirable for epitaxial growth, so it is important to monitor and control it when developing growth recipes in which Si (or Ge) is annealed under AsH 3 .…”

In situ study of Ge(100) surfaces with tertiarybutylphosphine supply in vapor phase epitaxy ambient

“…Low energy electron diffraction (LEED) analysis of a P-terminated Ge(100) surface with 2° offcut prepared by PH 3 exposure in MOVPE ambient shows a (9 x 2) surface reconstruction [10]. In contrast to AsH 3 , PH 3 does not etch the Ge surface [13]. However, the influence of annealing under TBP on the Ge(100) surface is still not clear.…”

An STM and LEED study of MOCVD-prepared P/Ge (1 0 0) to (1 1 1) surfaces

“…This is a problem, because arsine etches Ge, often producing rough surfaces and poor GaAs/Ge epitaxy [1]. With a GaInP 2 buffer layer, the GaAs/ GaInP 2 /Ge growth sequence exposes the Ge substrate to phosphine instead of arsine.…”