H. Kühne

Chemical vapour deposition of epitaxial SiGe thin films from SiH4GeH4HClH2 gas mixtures in an atmospheric pressure process

Abstract Chemical vapour deposition of epitaxial SiGe-layers from SiH 4 , GeH 4 , H 2 and HCl gas mixtures has been studied experimentally at atmospheric pressure. The results obtained and those of other authors have been compared with a simple mass-transport-reaction limited deposition model which seems to be valid over a wide range of total pressures and temperatures.

Suppression of epitaxial silicon layer doping with boron in the presence of hydrogen chloride

The present paper informs about thermodynamic calculations of the BClH system, carried out irrespective of data, already published by other authors. It further deals with recent experimental results on silicon doping with boron in the presence of hydrogen chloride, the layer growth rate being varied. Finally the possibility of quantitatively interpreting the suppressing influence of hydrogen chloride on the doping of silicon with boron is discussed. Die vorliegende Arbeit informiert uber thermodynamische Berechnungen zum BClH System, die unabhangig von bereits veroffentlichten Ergebnissen anderer durchgefuhrt wurden, uber neuere experimentelle Ergebnisse zum Boreinbau wahrend der epitaktischen Silizumabscheidung in Gegenwart von Chlorwasserstoff und bei unterschiedlichen Werten der Schichtwachstumsrate, sowie uber die Moglichkeit zur quantitativen Beschreibung der Herabsetzung des Boreinbaus in Gegenwart von Chlorwasserstoff.

Oxygen incorporation and oxygen‐induced defect formation in thin Si and Si1−xGex layers on silicon grown by chemical vapor deposition at atmospheric pressure

The incorporation of oxygen into thin epitaxial Si and heteroepitaxial Si1−xGex layers deposited, applying a conventional atmospheric pressure process, from silane, germane, hydrogen chloride, and hydrogen gas mixtures in a temperature range from 1070 to 720 °C is analyzed. The role of oxygen for defect formation has been shown by means of a correlation between high resolution defect analysis using transmission electron microscopy and quantitative oxygen depth profiling using Auger electron spectroscopy and secondary ion mass spectrometry. In the low‐temperature region traces of residual H2O vapor lead to oxygen precipitation. These precipitates are the origin of extended lattice defects such as stacking faults and microtwins and can result in highly defective films with polycrystalline inclusions and increased surface roughness. It was found that, in order to prevent the observed defects, it is necessary to keep the oxygen concentration below 3×1019 cm−3. However, by carefully controlling the experimenta...

Adsorption controlled Si(1−x)Gex growth during chemical vapor deposition

The present investigation concerns Si(1−x)Gex thin film growth that, at certain deposition conditions, is characterized by nonlinearity in the partial growth rate of germanium versus the increase of the germane (GeH4) content in the reaction gas mixture. A linear increase had previously been understood as caused by a reaction rate limited growth mechanism. The nonlinear increase of the partial growth rate of germanium versus the GeH4 partial pressure will be explained by means of an adsorption controlled growth mechanism based on competitive adsorption of both silane and germane. Transition from one to the other growth mechanism is possible as shown by the discussion of corresponding experimental growth results.

On epitaxial Si1−xGex thin film growth by chemical vapour deposition from a silane, germane, hydrogen chloride and hydrogen gas mixture

Abstract Epitaxial Si 1−x Ge x layers were deposited in a conventional atmospnheric pressure process from silane, germane, hydrogen chloride and hydrogen gas mixtures in the temperature range from 1070 to 730°C. A clear transition from strong to weak temperature dependence is observed at about 870 °C as typical fure silicon depositionn from silane. So a transport-reaction limited mechanism is deduced for SiGe layer growth. The theoretical consideration of growth mechanism is based on the assumption of three partial growth rates, the sum of which is equal to total layer growth rate. The partial growth rates consist of the silicon growth rate observed without germane in the gas, the germanium growth rate observed by the presence of germane in the gas, and the rate of additional silicon deposition caused by the presence of germane, too. Germanium partial growth rate is also characterized by a strong and weak region of temperature dependence; however, the transition is observed at about 980 °C.