$p(2\ifmmode\times\else\texttimes\fi{}2)$ Phase of Buckled Dimers of Si(100) Observed on $n$-Type Substrates below 40 K by Scanning Tunneling Microscopy

$p (2 \times 2)$ Phase of Buckled Dimers of Si(100) Observed on $n$ -Type Substrates below 40 K by Scanning Tunneling Microscopy

Kenji Hata, Shoji Yoshida, and Hidemi Shigekawa

Phys. Rev. Lett. 89, 286104 – Published 30 December 2002

Abstract

We have investigated the basic surface reconstruction of Si(100) on well defined surfaces fabricated on various substrates at low temperatures ( $- 80 K$ ) by scanning tunneling microscopy. Below 40 K, the single $p (2 \times 2)$ phase, a phase never observed before, was observed exclusively on $n$ -type substrates doped in the range of 0.002 to $0.017 Ω c m$ . We also exclude the possibility of the ( $2 \times 1$ ) symmetric dimer commonly observed at low temperature ( $- 10 K$ ) being the basic surface reconstruction by showing that a buckled dimer can be flip-flopped by the tunneling tip.