Structural reordering and electrical activation of ion-implanted GaAs and InP due to laser annealing in a controlled atmosphere

Abstract

The effects of the ambient atmosphere in the annealing chamber on the electrical and structural characteristics of Zn-implanted III-V compound semiconductors, processed by low-power pulsed-laser annealing are presented. The samples were analyzed using several complementary experimental techniques: Reflection highenergy electron diffraction, Rutherford backscattering spectroscopy, Raman spectroscopy, secondary ion mass spectroscopy, and electrical measurements. During the laser beam irradiation in the presence of gas inlet into the annealing chamber the ambient gas atoms diffused well into the target changing the stoichiometry and the electrical parameters. Redistribution of the implanted impurity was also observed. By varying the type of gas used and its pressure, it was possible to achieve electrical activation of up to 80%. It seems all structure and electrical parameters achieve their best values at the same ambient atmosphere and density of the deposited laser power P, e.g., 1.5 atm of N 2 and Pϭ6.5 MW/cm 2 for InP.

Ferromagnetic Mn-Implanted GaP: Microstructures vs Magnetic Properties

“…The important fact is that its intensity increases with annealing energy. This is a similar behavior as for InP layers after PLA, , and indicates the formation of polycrystalline GaMnP film with misoriented domains. The LO peaks of 0.50 and 0.60 J/cm 2 annealed GaMnP exhibit a downward shift to the left side when compared with 0.45 J/cm 2 annealed sample, arising from two effects: (1) the CPLOM appears and shifts the LO peak to lower frequency and (2) the presence of strain introduced by crystalline domain boundaries and defects.…”

Epitaxial GaNxAs1-xlayer formed by pulsed-laser irradiation of GaAs in an ambient nitrogen gas

“…The fluence 0.20 J cm −2 corresponds to a power density of 8.7 MW cm −2 for the laser used. This value is very close to the critical power density (9 MW cm −2 ) of micromelting of the GaAs surface [17]. Thus the formation of an epitaxial GaNAs layer is strongly correlated to the instantaneous melting of the GaAs surface layers during the laser irradiation.…”

“…Pulsed-laser irradiation on materials in vacuum or an ambient gas can induce structural and chemical changes of surface layers [12][13][14][15][16][17]. The most relevant examples are nitriding the surfaces of metal (Ti) and semiconductors (Si, Ge) [14,16], and structural reordering of ion-implanted GaAs and InP due to the laser annealing effect [13,14,17].…”

“…Pulsed-laser irradiation on materials in vacuum or an ambient gas can induce structural and chemical changes of surface layers [12][13][14][15][16][17]. The most relevant examples are nitriding the surfaces of metal (Ti) and semiconductors (Si, Ge) [14,16], and structural reordering of ion-implanted GaAs and InP due to the laser annealing effect [13,14,17]. Moreover, in the latter case, it was found that during the laser beam irradiation in the presence of a gas inlet into the annealing chamber, the ambient gas atoms diffused well into the target and changed the stoichiometry and electrical parameters [17].…”

Migration barriers of neutral As di-interstitials in GaAs

“…Moreover, intrinsic interstitials have been demonstrated to play a crucial role in the diffusion processes of p-type dopants in GaAs [5,6]. However, differently from vacancy and antisite studies [7][8][9][10], pieces of experimental evidence for self-interstitials in III-V compound semiconductors are rare and indirect, being often inferred from diffusion experiments of dopant species [5,6,11,12] or from the observation of extended defects [13][14][15][16][17]. Theoretical predictions of the intrinsic interstitials' main properties in GaAs have been attempted since the beginning of the 1990s in the framework of the density functional theory (DFT) with limited computational resources [18,19]; then, this matter has recently been revised taking advantage of the enormous improvement in computational techniques and resources over the last 20 years [20][21][22][23][24][25][26][27][28].…”