Precipitation of oxygen in dislocation-free silicon

Abstract

a), I?. SPIEC:KLRRRG (a), €1. CLEICHMAKN (b), and I). \TRUCK (a)The precipitation of oxygen in bulk dislocation-free Czochralski silicon subjected to isothermal annealing at temperatures b e h e e n 400 and 1100 "C is studied by means of infrared spectroscopy and transmission electron microscopy. From the changes in the infrared spectra observed after heat treatment it is concluded that (i) for low annealing temperatures (400 to 750 "C) the precipitates consist of amorphous SiO, (x < 2) which with rising temperature is transformed into amorphous SiO,, (ii) a t medium annealing temperatures (750 to 950 "C) a-cristobalite precipitat,es are formed, which (iii) at high annealing temperatures (950 to 1100 "C) are converted in amorphous SiO,. I n transmission electron microscopy the temperature range (i) is characterized by the appearance of "rod-like'' defects and its transformation into dislocation loops, and the ranges (ii) and (iii) b y the observation of platelet-shaped precipitates generating dislocation loops and stacking faults, leading to the conversion of the platelet-shapcd precipitates into microprecipitates.Es wird die PrLzipitat.ion von Sauerstoff in versetzungsfreiem Czochralski-Silizi~~m nach isothermaler Warmebehandlung bei Temperaturen zwischen 400 und 1100 "C mit Hilfe der Infrarotspektroskopie und der Transmissions-Elektronenmikroskopie untersncht. Bus den Anderungen im lnfrarotspektruni, die nach der Warmebehandlung beobachtet werden, wird geschlossen, daB fur niedrige Temperungstemperaturen (400 bis 750 "C) die Prazipitate aus aniorphem SiO, (x < 2) bestehen, welches sich mit wachsender Temperatnr in amorphes SiO, umwandelt., daB bei mitbleren Temperungstemperaturen (750 bis 950 "C) a-Cristobalit-Prazipitate gebildet werden, die sich bei hohen Temperungstemperaturen (950 bis 1100 "C) in amorphes SiO, umwandeln. I n der Transmissions-Elektronenmikroskopie wird der erste Temperaturbereich durch das Auftreten von ,,stabchenformigen" Defekten und deren Umwandlung in Versetzungsschleifen charakterisiert und die beiden anderen Temperaturbereiche durch die Beobachtung von plattchenformigen Prazipitaten, die Versetzungsschleifen und Stapelfehler erzeugen, was schlieDlirh z u einer Umwandlung der plattchenformigen Prazipitate in Mikroprazipitate fuhrt.

On the treatment of primary extinction in diffraction theories based on intensity coupling

“…At temperatures above 820 K, oxygen forms precipitates as some form of silica. For annealing in the temperature range from approximately 920 to 1050 K, the dominant precipitate morphology is rodlike (Tempelhoff, Gleichmann, Spiegelberg & Wruch, 1979) and has been identified as coesite, a highpressure form of quartz (Bourret, Thibault-Dessaux & Seidmann, 1984;Ponce & Hahn, 1984). The silicon matrix around the evenly distributed precipitates is strained.…”

Impurity Reaction with Dislocations in Semiconductors

“…The first is the temperature region lower than 650 C (low temperature range) where precipitates are of the shape of a small sphere with a diameter of order of 2 nm [9]. The second is the temperature range of 850 to 1000 C (intermediate temperature range) where precipitates are of the shape of a square-shaped platelet with the habit planes f100g and the edges parallel to the h011i directions [10]. Such a platelet-like precipitate is accompanied by a lattice strain of the matrix region and often emits punched out prismatic dislocation loops.…”

IR studies of the oxygen and carbon precipitation processes in electron irradiated tin-doped silicon

“…Additionally, they may act in conjunction with surrounding defects, as recombination centers reducing the efficiency of the corresponding devices. Depending upon the thermal history of the material and the temperature of the thermal treatments O precipitates have different forms and morphologies [10,11] giving rise to a number of IR bands [32][33][34] in the spectral region of 1000-1300 cm −1 , around the strong IR band of oxygen at 1107 cm −1 . Notably, the formation of SiO x precipitates is accompanied by a volume increase, which induces compressive strains in the Si lattice.…”