Electron-beam-induced crystallization of isolated amorphous regions in Si, Ge, GaP, and GaAs

Abstract

An energetic electron beam has been used to stimulate crystallization of spatially isolated amorphous regions in Si, Ge, GaP, and GaAs at 30 and 300 K. In the four materials it was found that crystallization was induced even when the energy of the electron beam was less than that required to create point defects in the crystalline structure. The rate of crystallization depended on the material and on the electron energy. In all materials, the rate decreases as the electron energy increases from 50 keV (the lowest electron energy used), reaching a minimum value at an electron energy slightly below the displacement threshold voltage. Above the displacement threshold, the regrowth rate again increases with increasing electron energy. The possible role of electron-beam heating was studied both theoretically and experimentally. Calculations suggested heating effects were negligible and this was confirmed by in situ ion implantations and electron irradiations performed at 30 K, where subthreshold electrons stimulated crystallization. The subthreshold and low-temperature results are consistent with the model that the crystallization process is dependent on the creation of defects (dangling bonds and kinks) at the crystalline-amorphous (c-a) interface. The crystallization stimulated by the subthreshold electron beams suggests that electronic excitation of the bonds along the c-a interface can induce the amorphous to crystalline transition.

RBS and TEM studies of indium phosphide irradiated with 100 keV Au ions

“…More recent TEM observations of isolated zones following ion irradiation have been reported in the compound semiconductors GaAs, GaP, InP (in addition to the elemental semiconductors Si and Ge) [1, 5, 15, 16Ä21]. However, the authors assumed that the observed zones in all the compound and elemental semiconductors investigated were amorphous in nature, based on TEM observations of zones for only GaAs irradiated with heavy ions [22] which appear as dark contrast irregular features in conventional TEM.…”

Influence of TEM low energy electron irradiation on InP damage structure irradiated previously by 100 keV Au ions

“…The results of radiation zones accumulation under Au (100 keV) irradiation versus uence and ion energy with the use of TEM and RBS/C analysis and a phenomenological model of core creation are presented in [2] and [7], respectively. In Fig.…”

“…Using of Rutherford Backscattering Technique (RBS) and Transmission Electron Microscope (TEM) damage structure of irradiated InP SSCS versus the ion uences was studied. Recently, it has been demonstrated that electron irradiation at an energy lower than the threshold energy required to produce direct atomic displacement (point defects) has resulted in zone shrinkage and disappearance in several elemental and compound semiconductors [1,2]. The disappearance rate of thermally and laser-induced recovery of these zones was compared to the electron beam-induced recovery process, it was found that the electron beam-induced recovery was more efˇcient (judging by the disappearance rate versus elapsed time) than theˇrst two processes [3].…”

Single-atom fabrication with electron and ion beams: From surfaces and two-dimensional materials toward three-dimensional atom-by-atom assembly

“…One example is beaminduced crystallization and amorphization. This area was actively explored in the 1980s and 1990s, and e-beam crystallization of a number of important semiconductors such as Si [49][50][51][52] and GaAs [52][53][54] has been reported. Similarly, the beam can result in selective removal of material, and when integrated with beam-induced reactions, it can enable fabrication of nanoscale structures, as summarized in recent reviews by Krasheninnikov,55 Gonzales-Martinez, 56 and Jesse.…”