GaAs epitaxial growth for field effect transistors

gate, source and substrate and gate controlled pnn+ structures are compared when used as a protective input device on p-channel MOS integrated circuits. For this purpose two pulse techniques are developed which allow an accurate determination of the dynamic resistance by minimising the walk-out of the breakdown voltage during the measurement. While the breakdown voltage does not differ much for the different types of devices, the dynamic resistance however is found to be considerably lower for the MOS transistor than for both other devices. For these low values the series resistance of the drain and source diffusion is shown to constitute already an important contribution. The lower dynamic resist3. Discrete Devices ance of MOSTs can be ascribed to parasitic bipolar transistor operation during breakdown. The identificaMembrane touch switches: thick-fiLm materials systems tion of this mechanism leads to a simple model for the and processing options MOS transistor in breakdown which has been experiW. T. HICKS, T R E V O R R. ALLINGTON and VAN mentally verified and confirmed. Guidelines for the IOHNSON definition of the source diffusion for an optimal pro[EEE Trans. Components, Hybrids, Manuf. TechnoL tective functioning can be obtained from this model. UHMT-3(4) 518 (December 1980). Fhick-film materials and processing parameters critical 4. Materials to the production of membrane touch switches are reviewed. The primary emphasis is on polymer-bonded On the correlation of "hot" and "cold" electron-hole filver conductor systems; electrical conductivity versus drop densities in uniaxially stressed silicon filver content, conduction mechanisms, techniques to J. WAGNER, A. FORCHEL and R. SAUER -letermine adhesion, materials for screen printing, Solid-St. Commun. 36, 917 (1980). :hoice of Mylar :~ polyester film, and appropriate drying "Hot" and "cold" electron-hole drops were studied in :onditions are discussed. Also described is the perfor- <100>-stressed silicon by intense optical pulse excitation nance of a new series of polymeric resistors on various and gated photoluminescence measurements. We obtain ;ubstrates (including Mylar ~ polyester), under different varying relative densities of hot and cold EHD electrons :uring and storage conditions. Future trends in the either by choosing the delay time of the gate appropriately levelopment of materials systems for membrane or by using samples of different impurity concentrations. ;witches and associated circuitry are also briefly In aU cases, the spectra can entirely be fitted assuming reviewed. only a homogeneous EHD-phase consisting of both, hot and cold electrons. This result is in agreement with recent Stress-sensitive properties of silicon-gate MOS devices theoretical work which - contrary to germanium - finds phase separation in stressed silicon not to be very likely. HIROAKI MIKOSHIBA Solid-St. Electron. 24, 221 (1981). Analysis of the effect of mechanical stress on the effective Stress-sensitive properties were measured on both p - mobility of charge carriers in inversion layers of P[MOS and n-channel silicongate MOS devices fabricated.on structures (100) Si at room temperature. Stress-induced variations WOJCIECH WLODARSKI and in drain currents for both enhancement- and depletionBOGDAN MOESCHKE mode MOS transistors with various channel-dopings were measured over a wide range of gate biases. In Electron. Technol. 12(3) 31 (1979). addition to piezoresistance effect, remarkable drain- The paper presents a critical discussion of the effect of :urrent variations were observed at weak-inversion and various factors on the effective mobility of holes in .~xplained theoretically in terms of changes in minority reversion layers of P/MOS structures. The effect of densities due to energy band shifts by stresses. Elasto- mechanical stress on the mobility is analysed. The 9esistance shear-constants for polycrystalline-silicon influence of individual electrophysical parameters of the ,ate layers were also obtained and compared with co- structure on the effective mobility is considered and the ;fficients for source-drain diffused layers. Further, the relation/zef = f(o-) is determined. The results of theoreti:lastoresistance of p-type polycrystalline-silicon films cal considerations are compared with experimental vas investigated on doping-concentration dependences. data. theoretical model for polycrystalline-silicon elasto- GaAs epitaxial growth for field effect transistors 'esistance was developed based on the barrier model for :onductivity in polycrystalline-silicon. Results obtained J. P.CHANE and J. HALLAIS ~rom the model were compared with the experimental Acta Electron. 23(1) 11 (1980) (in French). 9esults and found to be in good agreement at higher A survey of the characteristic properties of the material used for field effect transitor (FET) is presented. The loping-concentrations than trap density. main available methods - vapour phase, liquid phase Lmodel for the breakdown characteristics ofp-channel and molecular beam epitaxy - are comparatively discussed. The vapour phase growth and more specifically ,lOS transistor protection devices the arsenic trichloride method with liquid gallium source t. MAES, P. SIX and W. SANSEN (AsCI3/GalH2 method) is described. It is shown that this "olid-St. Electron. 24, 523 (1981). technique is well suited to the growth of FET structures ~ate controlled diodes, MOS transistors with grounded and can be easily industrialised.

Britain takes the lead on hybrid components Electron. Prod. p. 5 (August 1981). For the moment, Britain takes the lead since no other European country has an approval scheme for hybrid components for high reliability circuits. The new BSg0(X) scheme for "assessors of add-on components" was necessary because hybrid microcircuits frequently use high technology hybrid components (often manufactured only off-shore) which need to be qualified within the BS9000 scheme if the hybrids are used in high reliability of military projects.

79

m and carbon in Czochraiski-grown silicon ING LIAW ,electron. J. 12(3) 33 (1981). mrpose of this paper is to review the subject of n and carbon in silicon crystals in terms of: (1) origin and concentration; (2) their effect on the .tion of crystalline defects and the impact of these '. devices; and (3) the industrial trends regarding .~ms related to oxygen and carbon.

5.

Production and Processing

netal thick-film conductors ;TEIN, C. H U A N G and L. CANG .St. Technol. 73 (January 1981). metal conductive thick-films formed by firing in air iscussed. The metals under study include nickel, lium, aluminium and copper. The properties of the ire presented for firing temperatures ranging from 851YC. Compatibility with various dielectrics and s have been studied. Specialised multilayer uses feasible. Potential uses on porcelain enameled window glass and alumina substrates are reviewed ata are supplied. Difficulties in bonding, joining ontacting these materials are described. Initial s have been made of c,,mpatibility with thick-film 1lure-based resistors. Some data on termination mce problems and other properties observed in :nations of base and precious metals are presented. Die applications in gas discharge displays for tes and conductor runs are discussed. Potential nay include ground planes, solar cell electrodes raristor, thermistor and other passive device rations. r and doping uniformity of ion implantation nent PERLOFF, J. N. G A N and E E. W A H L St. TechnoL 112 (February 1981). Romated technique for characterising the dose tcy and doping uniformity of ion implantation nent is described. This technique involves perIg four-point probe sheet resistance measureon implanted and annealed silicon wafers. Two :ndent current/voltage configurations are used at .'st site to eliminate geometric sources of measure.'trot, making it possible to display the data in the of high-resolution contour maps and diameterResults of a survey involving eighty-five producnplanters are presented which demonstrate the ness of this technique for cross-calibrating ion ltation equipment.

' contacts to si-lmplanted InP lI Y A M A G U C H I , TAKASHI NISHIOKA DSHIRO OHMACHI ft. Electron. 24,263 (1981). : contacts to Si-implanted, n + layers on semi:ing InP are investigated on the basis of the transn line model. It is found that A u / N i / A u G e N i / I n P t shows a good ohmic behaviour with the specific t resistance pc of 2 • 10-Sf~cm2 and the minimum t resistance Zc of --2 • 10-3f/cm for a Si-dose than 2 • 1014cm-2 at 100 or 200keV. The results :e that, in the FET fabrication, at least 120p.m in is necessary in order to obtain source and drain ,des with minimised resistance.

Contribution to range statistics of Boron implanted into Silicon at high energies A. G. K. LUTSCH, C. A. B. BALL, F. D. A U R E T and H. C. SNYMAN Microelectron. J. 12(2) 25 (1981). The theoretical distribution of implanted Boron in Silicon as computed by Gibbons et al. shows physically unrealistic negative values for energies higher than 100keV. The distribution for B in Si has been measured by Auger Electron Spectroscopy for an implant energy of 300keV. It was found that the third moment as computed by Gibbons is too high. A good curve fitting with the experimental data can be obtained by a simplified Edgeworth distribution with half the third moment value proposed by Gibbons. Implant distributions are predicted for higher energies.

6. Testing A modular method for LSI circuits testing G. JASINEVITCHENE, B. BURGIS and E. METSAEV Proc. C N E T Conference on Reliability and Maintainability, Tregastel, France, p. 1 (8-12 September 1980). A method for large-scale integrated (LSI) circuits testing is presented which enables to investigate LSI circuit as a composition of several simple parts: There are three stages of this method: (1) circuit partitioning into modules,(2) test generation for each module, (3) the circuit test compilation from test sets for modules. The problems of these stages have been revealed and a reasonable solution has been suggested.

Multi-scan electron beam sintering of AI-Si OHMIC contacts M. FINETYI, S. SOLMI and G. SONCINI Solid-St. Electron. 24, 539 (1981). Experiments on sintering of AI-Si ohmic contacts by scanning electron beam annealing are presented and discussed. Special test patterns have been used to measure the contact resistivity, while diode reverse current density has been checked to evaluate the junction leakage induced by the aluminum silicon interaction during sintering. Electron beam annealing allows to obtain contact resistivities of the order of 10-5Ilcm 2, i.e. typical of conventional thermal sintering, while avoiding or strongly reducing the interdiffusion at the metal-silicon interface. High quality aluminum contacts on 0.31tm phosphorus diffused junctions have been made by 20keV electron beam sintering at 0.25A/cm 2 current density with negligible increase in junction leakage, while conventional thermal sintering, carried out for comparison, failed as expected due to heavy leakag6 induced by localised interdiffusion. System performs complete SLIC tests HARVEY J. HINDIN Electronics. 207 (24 March 1981). Tester automates direct transmission measurements of interface circuits to be used in PCM communications systems.