The acceptor compensation in polishing of p-type silicon with ammonia or amine-containing silica sol slurries has formerly been explained by the well-known inactivation of boron with atomic hydrogen or by the action of lattice selfinterstitials. We give evidence by neutron activation analysis, energy-dispersive x-ray analysis, secondary ion mass spectroscopy and photoluminescence spectroscopy that traces of copper in the slurry are responsible for this effect. A mechanism for the chemomechanical polishing of silicon and the incorporation of copper into the wafer is suggested.
The deactivation of the acceptor indium after chemomechanical polishing of p-type silicon is shown to result from the formation of a complex involving the indium atom and a positively charged, extremely fast-diffusing defect X. In the temperature range from 220 to 280 K, the dissociation frequency ν of this complex and the diffusion coefficient D of the defect X are thermally activated and satisfy the expressions ν=ν0 exp(−Ed/kT) and D=D0 exp(−Ea/kT) with ν0=2.6×1012 s−1, Ed=0.690 eV, D0=5×104 cm2/s, and Ea=0.665 eV.
The chemomechanical polishing mechanism is described as a corrosive attack of water forming Si-H and Si-OH groups. By adding ammonia or amines to the slurry we observe an irlfease of the resistivity corresponding to a neutralization of up to 1 × 1017 acceptor atoms cm−3 in the case of p-type silicon, whereas n-type silicon can show a slight reduction in resistivity due to the neutralization of the residual acceptor concentration.SIMS measurements show the presence of hydrogen in the bulk. Using deuterium instead of hydrogen, a correlation could be established between the deuterium content of the wafer, measured by the effusion technique, and the degree of the acceptor compensation.As can be shown by resistivity and C/V-measurements, under the conditions of polishing the supposed inactivator hydrogen migrates to a distance finally corresponding to the thickness of a wafer. This is contrary to the comm on method of plasma treatment, where a damaged silicon layer is supposed to act as a barrier to the hydrogen diffusion. Differences in the IR spectra can be explained this way.Crystal imperfections in the bulk and on the surface influences the migration of hydrogen essentially.
Es werden Verfahren zur Darstellung von Diisopropyl-und Di-tert-butylboranen RzBX (X = F, C1, Br, I, OR', SCH3, NH2, NHR' und NR',) beschrieben, die von den leicht zuganglichen (Dimethy1amino)diorganylboranen 2a, b ausgehen. Diese erhalt man durch Alkylierung des (Dimethy1amino)dioxaborolans 1 a mit (CH&CHMgBr bzw. (CH3)+2Li. Der EinfluS der raumerfiillenden Gruppen R auf die Reaktivitat wird an einer Reihe von Beispielen aufgezeigt. Y ---Boran-Derivate rnit sperrigen Organylgruppen am Bor-Atom sind mit Ausnahme der Dime~itylborane~) vergleichsweise wenig untersucht. Letztere zeigen zwar in ihrem chemischen Verhalten eine Reihe von Eigenschaften, die fur sterische Hinderung bei nucleophilen Substitutionsreaktionen typisch sind, jedoch belegen spektroskopische Untersuchungen"), daO die BN-Bindungsverhaltnisse eher dem Typ A entsprechen.Di-tert-butylborane, die ebenfalls erhebliche sterische Effekte aufweisen sollten, sind in der Literatur noch kaum beschrieben. Dies gilt auch fur Diisopropylborane. Wir berichten daher iiber die Darstellung und Reaktionen dieser Diorganylborane sowie in der nachfolgenden Arbeit") uber kernresonanzspektroskopische Untersuchungen an diesen Verbindungen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.