Showing papers by "Stephen J. Pearton published in 1985"
TL;DR: In this paper, the authors show that hydrogen penetration depth into GaAs(Si) is inversely dependent on the Si concentration, and that the free-carrier concentration can be restored by heating at 420°C for less than 3 min.
Abstract: Hydrogen plasma exposure of n‐type GaAs(Si) at 250 °C results in a decrease of the free‐carrier concentration by several orders of magnitude. This neutralization effect has been demonstrated in silicon‐doped layers grown by molecular beam epitaxy or formed by annealed implants as well as in bulk material. The same effect is produced electrochemically (H3PO4 electrolyte), whereas helium plasma exposure has no effect, thus confirming the role of hydrogen insertion. The hydrogen penetration depth into GaAs(Si) is inversely dependent on the Si concentration. Recovery of the electrical activity follows first order dissociation kinetics with a dissociation energy of 2.1 eV. Complete restoration of free‐carrier concentration occurs by heating at 420 °C for less than 3 min. Extrapolated to low temperatures, these results imply many years of stability at 150 °C or below.
221 citations
AT&T1
TL;DR: The ability of hydrogen to migrate in crystalline Si at low temperatures (<400°C) and bond to a variety of both shallow and deep level impurities, passivating their electrical activity, is of fundamental and technological interest as discussed by the authors.
Abstract: The ability of hydrogen to migrate in crystalline Si at low temperatures (<400°C) and bond to a variety of both shallow and deep level impurities, passivating their electrical activity, is of fundamental and technological interest. Recent results on the deactivation of the shallow acceptors in Si are compared with similar experiments in other semiconductors, microscopic models are proposed, and the implications for the states of hydrogen in the Si lattice at a variety of temperatures, and the diffusivity of some of these different states, is discussed. New results on the migration of atomic hydrogen under electronic stimulation are also detailed, along with a compendium of the deep levels in Si passivated by reaction with hydrogen. Surface damage by hydrogen-containing plasmas, and the infrared and electrical properties of H-related defect complexes are also reviewed.
35 citations
31 citations
TL;DR: In this article, a detailed study of transient thermal processing of S-doped epitaxial GaAs wafers, both with and without ion-implantation damage being present, has been performed.
Abstract: A detailed study of transient thermal processing of S‐doped epitaxial GaAs wafers, both with and without ion‐implantation damage being present, has been performed. The average diffusivity of S is given for the temperature range 950–1050 °C, and is shown to be dependent on the position of any lattice damage present, the surface condition (capped or capless), and the annealing regime employed (thermal or rapid thermal). The mobility of the S‐doped region is degraded by rapid annealing, and the extent of this degradation is a function of the experimental conditions employed. Implantation of Si (which occupies a Ga site) into S‐doped n+ regions (S occupies an As site) failed to increase the electrical activity of the region above the often observed limit of 2×1018 cm−3.
31 citations
TL;DR: The acceptor-protonic trap pair model (A−H+) of Sah, Pan and Hsu [J. Appl. Phys. 57, 5148 (1985) was used in this article to show that acceptor compensation is unstable under minority (electron) carrier injection by forward bias or illumination at 25°C.
Abstract: Transport of the hydrogen-related, acceptor-compensating defect has been observed in reverse-bias annealed Al-gate Schottky and n+-P diodes from hydrogenated, B-doped p-Si. Secondary ion mass spectroscopy (SIMS) profiling (deuterium substitution) confirmed field-aided migration. Significant differences in field transport (and thermal diffusion) between diodes from Hand D-treated p-Si(B) qualitatively indicates a monatomic species. The effect is interpreted as field drift of a positively charged species, possibly H+, with a donor charge state in the upper-half band gap, in conflict with long-held theory predicting very deep level activity. Acceptor compensation is unstable under minority (electron) carrier injection by forward bias or illumination at 25°C, supporting the acceptor-protonic trap pair model (A−H+) of Sah, Pan and Hsu [J. Appl. Phys. 57, 5148 (1985)].
26 citations
TL;DR: In this paper, the formation of p channel (p∼3×1017 cm−3) and p+ regions (p>5×1018 cm −3) in GaAs by rapid annealing of Be, Mg, Zn, or Cd implants at 900-950 °C is reported.
Abstract: The formation of p channel (p∼3×1017 cm−3) and p+ regions (p>5×1018 cm−3) in GaAs by rapid annealing of Be, Mg, Zn, or Cd implants at 900–950 °C is reported. The electrical characteristics of each species were investigated by capacitance‐voltage profiling, Hall‐effect and microwave photoconductance measurements, and particular emphasis was placed on determining the uniformity of activation over 2‐in.‐diam wafers. The results demonstrate that rapid thermal annealing is well suited to GaAs integrated circuit applications.
23 citations
AT&T1
TL;DR: The electrical activity of the oxygen-related thermal donors in heat-treated, P-doped, Czochralski grown Si is passivated by reaction with atomic hydrogen.
Abstract: The electrical activity of the oxygen-related thermal donors in heat-treated, P-doped, Czochralski grown Si is passivated by reaction with atomic hydrogen. Secondary ion mass spectrometry and spreading resistance profiles on deuterium plasma treated samples show a direct correlation between the deuterium incorporation depth and the distance over which the thermal donors are passivated. The donor activity is restored by annealing above 400°C, and comparison with other defect dehydrogenation data suggests that the thermal donors may contain Si dangling bonds. Results obtained from deep level transient spectroscopy measurements are used to illustrate the observed donor passivation and reactivation kinetics.
15 citations
TL;DR: A comprehensive review of the use of transient thermal processing for the activation of implanted dopants, the alloying of ohmic contacts, the pulse diffusion of Zn for p+ contacts, and other heat treatments of GaAs is presented in this article.
Abstract: A comprehensive review is presented of the use of transient thermal processing for the activation of implanted dopants, the alloying of ohmic contacts, the pulse diffusion of Zn for p+ contacts, and other heat treatments of GaAs In all cases, transient processing produces results at least as good as furnace heating, and in some instances, markedly better The special needs of GaAs, such as encapsulation of the wafer surface, and prevention of slip and warpage are discussed, as well as recent results detailing implant damage removal processes during transient annealing
9 citations
TL;DR: In this article, the removal of lattice damage and consequent activation by rapid thermal annealing of implanted Si, Se, Zn and Be in GaAs was investigated by capacitance-voltage profiling, Hall measurements, transmission electron microscopy (TEM), secondary ion mass spectrometry and Rutherford backscattering.
Abstract: The removal of lattice damage and consequent activation by rapid thermal annealing of implanted Si, Se, Zn and Be in GaAs was investigated by capacitance-voltage profiling, Hall measurements, transmission electron microscopy (TEM), secondary ion mass spectrometry and Rutherford backscattering. The lighter species show optimum electrical characteristics at lower annealing temperatures (∼850°C for Be, ∼950°C for Si) than the heavier species (∼900°C for Zn, ∼1000°C for Se), consistent with the amount of lattice damage remaining after annealing. TEM reveals the formation of high densities (107 cm−2) of dislocation loops after 800°C, 3s anneals of high dose (1×1015 cm−2) implanted GaAs, which are gradually reduced in density after higher temperatures anneals (∼1000°C). The remaining loops do not appear to effect the electrical activation or carrier mobility in the implanted layer, the latter being comparable to bulk values.
4 citations
TL;DR: In this paper, a new group of deep donors, designated ETI, has been studied in as-grown n-type ultrapure germanium single crystals (ND - NA)~1010 cm-3, which have a broad band-type structure consisting of three or more closely spaced peaks (Ec -40 meV to Ec -100meV).
Abstract: A new group of deep donors, designated ETI, has been studied in as-grown n-type ultrapure germanium single crystals [(ND - NA)~1010 cm-3]. The donors have a broad band-type structure consisting of three or more closely spaced peaks (Ec -40 meV to Ec -100meV) as determined by deep level transient spectroscopy (DLTS). Reverse electrode germanium (REGe) radiation detectors which contain ETI are shown to exhibit electron trapping leading to a degradation in resolution as measured by the 1.33 MeV ?-ray peak of 60Co. The concentration of ETI and the degradation in resolution are strongly correlated.
3 citations
TL;DR: In this paper, microwave photoconductance, capacitance-voltage profiling and Hall effect measurements were used to investigate the uniformity of activation of Si, Be and Mg implanted 2-and 3-inch GaAs substrates after rapid thermal annealing in a commercial furnace.
Abstract: Scanning microwave photoconductance, capacitance-voltage profiling and Hall effect measurements were used to investigate the uniformity of activation of Si, Be and Mg implanted 2″ and 3″ diameter, semi-insulating GaAs substrates after rapid thermal annealing in a commercial furnace. The results indicate that carrier lifetimes and mobilities for low dose (3−4 × 1012 cm−2) implants and carrier densities for high dose (1× 1015 cm−2) implants are comparable or superior in rapidly annealed substrates to those obtained in thermally annealed implanted layers. The uniformity of these parameters is not significantly different for wafers annealed by either method. The temperature dependence of damage removal and carrier activation in the implanted regions during both furnace and transient annealing was also investigated, and demonstrates that the microwave photoconductance technique gives results for donor implantation correlating well with conventional backscattering and electrical measurements respectively.