Quantitative theory of retarded base diffusion in silicon n-p-n structures with arsenic emitters
- 1 January 1973
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 44 (1), 283-291
- https://doi.org/10.1063/1.1661875
Abstract
When As is sequentially diffused into Ga or B‐doped Si, a retardation of the p ‐type base layer is generally observed. This is in contrast to the ``emitter‐push'' effect associated with sequential phosphorus diffusions. In order to simulate transistor profiles it is necessary to be able to quantitatively describe the emmiter‐base interactions during diffusion. In this study, the way in which the internal electric field, the equilibrium vacancy density, ion pairing, and the rate of [V SiAS2] complex formation affect the redistribution of the base layer during sequential processing was investigated. Numerical solutions to coupled diffusion equations indicate that the electric field and ion‐pairing effects only cause localized retardation of a B profile during the As emitter diffusion. However, the formation of [V SiAs2] complexes causes a vacancy undersaturation in the Si to a distance in the crystal well beyond most practical collector‐base junction depths. Since the local‐base diffusivity depends upon the vacancy density, this extrinsic vacancy undersaturation effect causes the expected retarded base diffusion. Experimental verification of the correctness of the theory present is given as a function of emitter‐ and base‐surface concentrations, initial base depths, and times and temperatures.Keywords
This publication has 18 references indexed in Scilit:
- Relationship between resistivity and total arsenic concentration in heavily doped n - and p -type siliconJournal of Applied Physics, 1973
- Reply to ``Discussion on `Approximate Theory of Emitter-Push Effect' ''Journal of Applied Physics, 1971
- Approximate Theory of Emitter-Push EffectJournal of Applied Physics, 1969
- Arsenic Isoconcentration Diffusion Studies in SiliconJournal of Applied Physics, 1969
- The Retarded Diffusion of Gallium in Silicon. IIJapanese Journal of Applied Physics, 1968
- Interactions in Sequential Diffusion Processes in SemiconductorsJournal of Applied Physics, 1968
- The Cooperative Diffusion EffectJournal of Applied Physics, 1966
- Localized Enhanced Diffusion in NPN Silicon StructuresJournal of the Electrochemical Society, 1965
- Distribution of Dislocations near the Junction Formed by Diffusion of Phosphorus in SiliconJapanese Journal of Applied Physics, 1964
- Chemical Interactions Among Defects in Germanium and SiliconBell System Technical Journal, 1956