Long range annealing of defects in germanium by low energy plasma ions

Abstract

Ions arriving at a semiconductor surface with very low energy (2 -8 eV) are interacting with defects deep inside the semiconductor. Several different defects were removed or modified in Sb-doped germanium, of which the E-center has the highest concentration. The low fluence and low energy of the plasma ions implies that the energy has to be able to travel in a localized way to be able to interact with defects up to a few microns below the semiconductor surface. After eliminating other possibilities (electric field, light, heat) we now conclude that moving intrinsic localized modes (ILMs), as a mechanism of longdistance energy transport, are the most likely cause. This would be striking evidence of the importance of ILMs in crystals and opens the way to further experiments to probe ILM properties both in semiconductors and in the metals used for contacts. Although most of the measurements have been performed on germanium, similar effects have been found in silicon.

Energy transfer in strained graphene assisted by discrete breathers excited by external ac driving

“…Later DBs were directly observed in many macroscopic and mesoscopic systems of different physical nature [4][5][6][7][8] . They have also been reported by experimentalists in different crystals, which can be regarded as nonlinear lattices if considered at the atomic scale [9][10][11][12][13][14][15] .…”

“…Velarde with co-authors argue that the localized excitations can contribute to the transport of electric charge [56][57][58] . DBs excited during low energy plasma surface treatment can participate in annealing of defects in single crystal germanium improving its quality for applications 14 . DBs are nonlinear vibrational modes and thus, they are most likely excited when the crystal receives energy in large portions, e.g., during optical driving, irradiation, under a high-density electric current, plastic deformation, etc.…”

Discrete breathers above phonon spectrum

“…Let us notice that in a 3D lattice the effective renormalized elastic spring 2 K is stronger than 2 K in the corresponding linear chain and condition (4) may be easier fulfilled in comparison with the condition (2). However, as a rule 2 K exceeds 2 K only a little (roughly 10÷20 %) and the increase of the ordinary value of κ < 0.5 is not sufficient.…”

“…These excitations are called as discrete breathers (DBs), intrinsic localized modes, vibrational solitons, or quodons [2,4,7,11,13,14,16,17,29,31,32,34,42,43,46,47,48,51,52]. In numerical studies of DBs different twobody potential models (Morse, Lennard-Jones, Born-MayerCoulomb and other potentials) have been used.…”

Возбуждение Щелевых Дискретных Бризеров В Кристалле Состава a-=sub=-3-=/Sub=-B Потоком Частиц

“…Приведем лишь несколько примеров. Ионно-плазменная обработка поверхности монокристаллов гер-мания высокой чистоты привела к отжигу дефектов на глубине в несколько микрон [1,2]. Воздействие плазмы сводится к бомбардировке поверхности кристалла иона-ми с энергией в диапазоне от 2 до 8 eV.…”