Formation of anomalously wide Si(111)root 3 x root 3 clean surface and itsstability

High-temperature scanning tunneling microscope observation has been perform ed to investigate formation of a Si(111)root3 x root3 structure and its sta bility on a quenched surface. Formation of anomalously wide Si(111)root3 x root3 domains was observed by increasing adatom density of Si on quenched s urface below the transition temperature between disordered "1 x 1" and orde red simple adatom structures. By adding Si adatoms most of the simple adato m structure transformed into the root3 x root3 structure. Domain boundaries between adjacent root3 x root3 domains are straight and along the (110) di rection, The root3 x v root3 structure transforms into the 2 x n structure by annealing and Si cluster increases in number to maintain Si adatom densi ty on the surface. This indicates that the 2 x n structure is energetically more stable than the root3 x root3 structure. (C) 2001 Elsevier Science BN . All rights reserved.