[Databa[Search[Result[RECORD[News][Exit] [Help] [ Database= Inspec | Search=au=("forbes | Results= 81 records | Records= 61, leonard") or 62, au=("forbes 63, l") 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80 ] --------------------------------------------------------------------------- [Email Records] --------------------------------------------------------------------------- Record: 61 RECORD NO.: 855742 INSPEC Abstract No: B76005130 AUTHOR: Forbes, L.; Wittmer, L.L. CORP SOURCE: Dept. of Electrical Engng., Univ. of Arkansas, AR, USA TITLE: Experimental verification of operation of the indium-doped infrared-sensing MOSFET SOURCE: IEEE Transactions on Electron Devices, vol.ED-22, no.12, p. 1100-1 ISSN: 0018-9383 CODEN: IETDAI PLACE OF PUBL: USA LANGUAGE: English YEAR: Dec. 1975 TREATMENT: X Experimental ABSTRACT: Verification demonstrating operation of the indium-doped silicon infrared-sensing MOSFET (IRFET) is provided. This is a new type of detector for the 3-5 mu m infrared wavelength regions, and the detector has been found to operate according to the original design proposal and criteria (8 Refs.) DESCRIPTORS: field effect transistors; infrared detectors IDENTIFIERS: In doped infrared sensing MOSFET; IRFET; IR detector CLASS CODES: B2560S (Other field effect devices); B7230C (Photodetectors) --------------------------------------------------------------------------- Record: 62 RECORD NO.: 827507 INSPEC Abstract No: B75041969 AUTHOR: Parker, W.C.; Forbes, L. CORP SOURCE: Dept. of Electrical Engng., Univ. of Arkansas, Fayetteville, AR, USA TITLE: Experimental characterization of gold-doped infrared-sensing MOSFET's SOURCE: IEEE Transactions on Electron Devices, vol.ED-22, no.10, p. 916-24 ISSN: 0018-9383 CODEN: IETDAI PLACE OF PUBL: USA LANGUAGE: English YEAR: Oct. 1975 TREATMENT: X Experimental ABSTRACT: The operation of a new type of infrared photon detector is described. This device is a gold-doped n-channel MOSFET that employs impurity photoionization to modulate its drain-to- source conductance. A simple mathematical model is developed whereby the infrared-sensing MOSFET (IRFET) can be analyzed, and experimental results that verify the model are provided. The near-infrared, i.e., wavelengths from 1.38 to 3.54 mu m, response of gold impurity centers in the space-charge region behind the strong surface inversion layer of a MOSFET is shown to correspond to the characteristics observed previously by other authors for the gold centers in bulk silicon. A static read-only memory capability and high responsivity, typically 4 mW/ mu J, are the most significant IRFET characteristics. Applications in large-scale- integrated imaging arrays are anticipated (23 Refs.) DESCRIPTORS: field effect transistors; infrared detectors; semiconductor device models IDENTIFIERS: infrared photon detector; impurity photoionization; IRFET; surface inversion layer; Au doped infrared sensing MOSFET's; drain to source conductance; space charge region; large scale integrated imaging arrays; read only memory capability CLASS CODES: B2560B (Semiconductor device modelling and equivalent circuits); B2560S (Other field effect devices); B7230C (Photodetectors) --------------------------------------------------------------------------- Record: 63 RECORD NO.: 800292 INSPEC Abstract No: A75062457; B75029162 AUTHOR: Forbes, L. CORP SOURCE: Dept. of Electrical Engng., Univ. of Arkansas, Fayetteville, AR, USA TITLE: Non-radiative recombination centers in GaAs/sub 0.6/P/sub 0.4/ red light-emitting diodes SOURCE: Solid-State Electronics, vol.18, no.7-8, p. 635-40 ISSN: 0038-1101 CODEN: SSELA5 PLACE OF PUBL: UK LANGUAGE: English YEAR: July-Aug. 1975 TREATMENT: X Experimental ABSTRACT: GaAs/sub 0.6/P/sub 0.4/ red light-emitting diodes constitute one of the most important commercial display technologies. The majority of the recombination in the p-n junction diodes is, however, non-radiative. This report describes the characterization of native defects in this material and provides evidence for non-localized, multiple and coupled- level defect centers. Thermal emission rates, photoionization cross sections, thermal capture coefficients and the distribution of these defects in the GaAsP substrate have been determined. These native defects result in a nsec non-radiative lifetime for holes injected into n-type material and non-radiative space charge recombination current at these centers can account for a large portion of the forward bias current in GaAsP red light-emitting diodes (21 Refs.) DESCRIPTORS: gallium arsenide; gallium compounds; III-V semiconductors; light emitting diodes IDENTIFIERS: p-n junction diodes; photoionization cross sections; thermal capture coefficients; space charge recombination current; nonradiative recombination centres; thermal emission rates; GaAs/sub 0.6/P/sub 0.4/ red light emitting diodes; defect centres CLASS CODES: A7340L (Semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions); A7860F (Electroluminescence)B2530B (Semiconductor junctions); B4260D (Light emitting diodes) --------------------------------------------------------------------------- Record: 64 RECORD NO.: 698360 INSPEC Abstract No: A74075953; B74038779 AUTHOR: Forbes, L.; Fogle, R.M. CORP SOURCE: Univ. Arkansas, Fayetteville, AR, USA TITLE: Photocapacitance investigation of defects in GaAs/sub 0.6/P/sub 0.4/ (p-n junctions) SOURCE: Applied Physics Letters, vol.25, no.3, p. 152-5 ISSN: 0003-6951 CODEN: APPLAB PLACE OF PUBL: USA LANGUAGE: English YEAR: 1 Aug. 1974 TREATMENT: X Experimental ABSTRACT: Photocapacitance transients are studied and a coupled multiple-level defect has been identified in n-type material which accounts for nanosecond non-radiative hole lifetimes in the material. The main level is found at 0.9 eV below the conduction band and is an energy often observed in both GaAs and GaP (21 Refs.) DESCRIPTORS: gallium arsenide; gallium compounds; III-V semiconductors; p- n homojunctions; photovoltaic effects; semiconductor defects IDENTIFIERS: photocapacitance; defects; GaAs/sub 0.6/P/sub 0.4/; n-type material; conduction band; GaAs; GaP; coupled multiple level defect; nanosecond nonradiative hole lifetimes CLASS CODES: A7155 (Impurity and defect levels); A7340L (Semiconductor-to- semiconductor contacts, p-n junctions, and heterojunctions); B2530B (Semiconductor junctions) --------------------------------------------------------------------------- Record: 65 RECORD NO.: 671402 INSPEC Abstract No: B74030673 AUTHOR: Forbes, L.; Yeargan, J.R. CORP SOURCE: Univ. Arkansas, Fayetteville, AK, USA TITLE: Design for silicon infrared sensing MOSFET SOURCE: IEEE Transactions on Electron Devices, vol.ED-21, no.8, p. 459-62 ISSN: 0018-9383 CODEN: IETDAI PLACE OF PUBL: USA LANGUAGE: English YEAR: Aug. 1974 TREATMENT: N New Development; P Practical ABSTRACT: A design is described for an infrared sensing MOSFET (IRFET). The high-gain high-resolution d.c. or static readout and inherent integrating and memory characteristics of the infrared sensing MOSFET should make it ideal for infrared imaging and target tracking applications employing a large-scale integrated array. The devices are based on silicon MOSFET technology where large-scale integrated arrays are routinely fabricated (11 Refs.) DESCRIPTORS: field effect transistors; infrared detectors; infrared imaging; large scale integration; phototransistors IDENTIFIERS: infrared imaging; target tracing applications; IR sensing MOSFET CLASS CODES: B2560S (Other field effect devices); B2570 (Semiconductor integrated circuits); B7230C (Photodetectors) --------------------------------------------------------------------------- Record: 66 RECORD NO.: 649737 INSPEC Abstract No: A74041435; B74023372 AUTHOR: Forbes, L.; Vaughn, C.K. CORP SOURCE: Univ. Arkansas, Fayetteville, AR, USA TITLE: Deep-level defects in red GaAs/sub 1-x/P/sub x/ light- emitting diodes SOURCE: Proceedings of the IEEE, vol.62, no.4, p. 534-5 ISSN: 0018-9219 CODEN: IEEPAD PLACE OF PUBL: USA LANGUAGE: English YEAR: April 1974 TREATMENT: X Experimental ABSTRACT: A wide variety of deep-level recombination centers have been observed at large concentrations in commercially available red GaAsP light-emitting diode p-n junctions. Similar defects have not been observed in GaP diodes. The characteristics, probable cause, and possible effect on luminescence efficiency of these deep-level defect centers are described (18 Refs.) DESCRIPTORS: gallium arsenide; III-V semiconductors; impurity electron states and effects; light emitting diodes; p-n junctions; semiconductor defects IDENTIFIERS: GaAs/sub 1-x/P/sub x/; effect on luminescence efficiency; red GaAs P light emitting diode p-n junctions; deep level defect centres; semiconductor defects CLASS CODES: A7340L (Semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions); A7860F (Electroluminescence)B2530B (Semiconductor junctions); B4260D (Light emitting diodes) --------------------------------------------------------------------------- Record: 67 RECORD NO.: 613708 INSPEC Abstract No: A74016830; B74010567 AUTHOR: Forbes, L.; Yeargan, J.R.; Keune, D.L.; Craford, M.G. CORP SOURCE: Univ. Arkansas, Fayetteville, AR, USA TITLE: Characteristics and potential applications of GaAs/sub 1- x/P/sub x/ MIS structures SOURCE: Solid-State Electronics, vol.17, no.1, p. 25-9 ISSN: 0038-1101 CODEN: SSELA5 PLACE OF PUBL: UK LANGUAGE: English YEAR: Jan. 1974 TREATMENT: X Experimental ABSTRACT: The characteristics of aluminum-Si/sub 3/N/sub 4/-GaAsP MIS capacitors are reported. High frequency C-V, and surface electroluminescence experiments have been conducted. It has been found that the generation rate of minority carriers in the surface space charge region is very low and the efficiency of the surface electroluminescence is high. Application of the MIS structures in displays based on surface electroluminescence is proposed and discussed (15 Refs.) DESCRIPTORS: capacitance; electroluminescence; gallium compounds; III-V semiconductors; luminescence of inorganic solids; luminescent devices; metal-insulator-semiconductor structures IDENTIFIERS: HF CV characteristics; surface electroluminescence CLASS CODES: A7340Q (Metal-insulator-semiconductor structures); A7860F (Electroluminescence); B2530F (Metal-insulator-semiconductor structures); B4260 (Electroluminescent devices) --------------------------------------------------------------------------- Record: 68 RECORD NO.: 546436 INSPEC Abstract No: B73028790; C73018977 AUTHOR: Sakamoto, H.; Forbes, L. CORP SOURCE: Univ. Arkansas, Fayetteville, AR, USA TITLE: Grounded load complementary FET circuits: Sceptre analysis SOURCE: IEEE Journal of Solid-State Circuits, vol.SC-8, no.4, p. 282- 4 ISSN: 0018-9200 CODEN: IJSCBC PLACE OF PUBL: USA LANGUAGE: English YEAR: Aug. 1973 TREATMENT: T Theoretical or Mathematical ABSTRACT: The performance of grounded load complementary MOS circuits has been evaluated. It has been found that a very significant improvement in performance and reduction in circuit-area might be achieved by employing grounded load devices in portions of a system employing large-scale integrated CMOS circuits (6 Refs.) DESCRIPTORS: computer-aided circuit analysis; field effect transistors; large scale integration; logic circuits IDENTIFIERS: Sceptre analysis; performance; grounded load complementary MOS circuits; circuit area reduction; large scale integration; logic circuits; computer aided circuit analysis CLASS CODES: B1130B (Computer-aided circuit analysis and design); B1260 (Pulse circuits); B1265 (Digital electronics); C7410D (Electronic engineering computing) --------------------------------------------------------------------------- Record: 69 RECORD NO.: 534774 INSPEC Abstract No: B73026092 AUTHOR: Forbes, L. CORP SOURCE: IBm Components Div., Manassas, VA, USA TITLE: n-channel ion-implanted enhancement/depletion FET circuit and fabrication technology SOURCE: IEEE Journal of Solid-State Circuits, vol.Sc-8, no.3, p. 226- 30 ISSN: 0018-9200 CODEN: IJSCBC PLACE OF PUBL: USA LANGUAGE: English YEAR: June 1973 TREATMENT: P Practical ABSTRACT: n-channel enhancement/depletion technology and circuits are described. The threshold voltage adjustment to form the enhancement- and depletion-mode devices are achieved by ion implantation. This allows optimization of the performance and circuit density. The calculated and experimentally observed speed-power product is 10 pJ/pF with a single +5-V power supply. Inversion of the field region on the high resistivity p-type substrate is completely eliminated by the use of an implanted field shield (6 Refs.) DESCRIPTORS: field effect transistors; integrated circuit production; ion implantation; monolithic integrated circuits; semiconductor device manufacture IDENTIFIERS: fabrication technology; performance; field inversion; high resistivity; FET circuit; depletion mode; n-channel; ion implantation optimisation CLASS CODES: B2550B (Semiconductor doping); B2560S (Other field effect devices); B2570 (Semiconductor integrated circuits) --------------------------------------------------------------------------- Record: 70 RECORD NO.: 509816 INSPEC Abstract No: B73015993; C73011572 AUTHOR: Forbes, L. CORP SOURCE: IBM, Manassas, VA, USA TITLE: N-channel ion-implanted enhancement/depletion MOSFET's SOURCE: IEEE Journal of Solid-State Circuits, vol.SC-8, no.2, p. 184- 5 ISSN: 0018-9200 CODEN: IJSCBC PLACE OF PUBL: USA LANGUAGE: English YEAR: April 1973 TREATMENT: X Experimental ABSTRACT: The fabrication and performance of n-channel ion-implanted, TTL compatible, enhancement/depletion MOSFET devices and circuits are described. A speed-power product of 10.0 pJ/pF has been experimentally observed (3 Refs.) DESCRIPTORS: field effect transistors; semiconductor device manufacture; transistor-transistor logic IDENTIFIERS: fabrication; performance; ion implantation; TTL; MOSFET CLASS CODES: B1260 (Pulse circuits); B1265 (Digital electronics); B2550B (Semiconductor doping); B2560S (Other field effect devices); C5120 (Logic and switching circuits) --------------------------------------------------------------------------- Record: 71 RECORD NO.: 419171 INSPEC Abstract No: B72027633 AUTHOR: Forbes, L.; Williams, T.A. TITLE: FET high-performance circuit and fabrication technology SOURCE: IBM Technical Disclosure Bulletin, vol.14, no.11, p. 3400-1 ISSN: 0018-8689 CODEN: IBMTAA PLACE OF PUBL: USA LANGUAGE: English YEAR: April 1972 TREATMENT: A Application; P Practical ABSTRACT: Complex logic functions operating at delay times of 15 to 20 nanoseconds can be achieved in metal-oxide semiconductor technology by (1) incorporating enhancement and depletion type devices in the same structure; (2) controlling leakage in the field-insulator region by a surface sandwich of phosphosilicate glass-aluminum trioxide-silicon dioxide, and (3) having a low-diffusion capacitance DESCRIPTORS: field effect devices; logic circuits; semiconductor device manufacture IDENTIFIERS: metal oxide semiconductor technology; field insulator region; low diffusion capacitance; phosphosilicate glass aluminium trioxide silicon dioxide; FET; fabrication; complex logic functions; delay times; enhancement; depletion type devices; controlling leakage CLASS CODES: B1260 (Pulse circuits); B1265 (Digital electronics); B2560S (Other field effect devices) --------------------------------------------------------------------------- Record: 72 RECORD NO.: 392855 INSPEC Abstract No: B72019274 AUTHOR: Forbes, L. TITLE: Automatic on-chip threshold voltage compensation SOURCE: IBM Technical Disclosure Bulletin, vol.14, no.10, p. 2894-5 ISSN: 0018-8689 CODEN: IBMTAA PLACE OF PUBL: USA LANGUAGE: English YEAR: March 1972 TREATMENT: P Practical ABSTRACT: Describes a circuit which compensates for variations in threshold voltage in field-effect transistors (FET) DESCRIPTORS: field effect transistors; integrated circuits IDENTIFIERS: automatic; threshold voltage compensation; FET CLASS CODES: B2570 (Semiconductor integrated circuits) --------------------------------------------------------------------------- Record: 73 RECORD NO.: 298909 INSPEC Abstract No: A71062152 AUTHOR: Forbes, L. CORP SOURCE: Univ. Illinois, Urbana, IL, USA TITLE: Thermal and optical emission and thermal capture of electrons and holes at gold centers in silicon SOURCE: p. 100 PLACE OF PUBL: USA LANGUAGE: English TREATMENT: X Experimental ABSTRACT: The method of dark current, capacitance and photocapacitance transients has been developed and applied to gold-doped silicon junctions. It has been demonstrated to be a very powerful method for the investigation of defect centers in semiconductors. Three thermal emission rates, three photoionization cross sections, and three thermal capture coefficients of the two-level system have been measured. Practical application of the results in high field M-O-S structures and the equivalent circuit technique are discussed. The concept of a field dependent relaxation time of impurity charge states in a high field region is introduced and described on the basis of a modification to the Shockley-Read-Hall model DESCRIPTORS: elemental semiconductors; impurity electron states and effects; silicon IDENTIFIERS: Au doped Si; thermal emission; optical emission; thermal capture; electrons; holes; dark current, capacitance and photocapacitance transients method; defect centres; semiconductors; photoionization; metal oxide semiconductor structures; impurity charge states; Shockley Read Hall model CLASS CODES: A7220 (Electrical conductivity phenomena in semiconductors and insulators); A7280C (Conductivity of elemental semiconductors) --------------------------------------------------------------------------- Record: 74 RECORD NO.: 293516 INSPEC Abstract No: A71059126 AUTHOR: Sah, C.T.; Ning, T.H.; Rosier, L.L.; Forbes, L. CORP SOURCE: Univ. Illinois, Urbana, IL, USA TITLE: Photothermal ionization via excited states of sulfur donor in silicon SOURCE: Solid State Communications, vol.9, no.12, p. 917-20 ISSN: 0038-1098 CODEN: SSCOA4 PLACE OF PUBL: USA LANGUAGE: English YEAR: 15 June 1971 TREATMENT: X Experimental ABSTRACT: Structures in the photoionization cross-section spectra below the extrinsic edge of the doubly charged sulfur donor (613 meV) are attributed to the two-step photothermal excitation process in which the bound electron at the ground state first makes an optical transition to an excited state and it is then thermally released from the excited state to the conduction band. A weak peak (cross-section 7*10/sup - 19/ cm/sup 2/) at 425 meV is attributed to the intervalley optical transition 2s(A/sub 1/) to 1s(T/sub 2/). Peak observed at 570 meV (10/sup -17/ cm/sup 2/) is attributed to the 1s(A/sub 1/) to 2p/sub 0/ intervalley optical transition and the peak at 591 meV (3*10/sup -17/cm/sup 2/) to the 1s(A/sub 1/) to 2p+or- intravalley optical transition. Data for electron bound at the neutral gold center has no structures which is consistent with the lack of excited states of a neutral impurity potential (12 Refs.) DESCRIPTORS: elemental semiconductors; ionisation of solids; photoconductivity; silicon IDENTIFIERS: Semiconductor; Si:S; photothermal ionization; excited states; photoionization cross-section spectra; doubly charged donor; optical transition; photoconductivity CLASS CODES: A7240 (Photoconduction and photovoltaic effects; photodielectric effects) --------------------------------------------------------------------------- Record: 75 RECORD NO.: 251893 INSPEC Abstract No: A71030828; B71015525 AUTHOR: Forbes, L.; Sah, C.T. CORP SOURCE: Univ. Illinois, Urbana, IL, USA TITLE: On the determination of deep level center energy and concentration by thermally stimulated conductivity measurements using reverse-biased p-n junctions SOURCE: Solid-State Electronics, vol.14, no.2, p. 182-3 ISSN: 0038-1101 CODEN: SSELA5 PLACE OF PUBL: UK LANGUAGE: English YEAR: Feb. 1971 TREATMENT: T Theoretical or Mathematical ABSTRACT: It is shown that in adopting the analysis in bulk sample to reverse-biased p-n junctions, an important physical difference between the depletion region of a junction and the quasi-neutral region of a bulk sample has been neglected: dielectric relaxation is very fast in bulk samples while it does not exist in the depletion region. Neglecting the displacement current results in an error of two in the deduced impurity concentration from integrating the thermally stimulated current up to the time of current maximum. The correct analysis for the depletion region of a junction is illustrated using a gold-doped silicon P+N junction which has been initially reverse biased at some low temperature DESCRIPTORS: impurity electron states and effects; p-n junctions; semiconductor junctions IDENTIFIERS: deep level center energy; concentration; thermally stimulated conductivity measurements; reverse biased p-n junctions; depletion region; displacement current; impurity concentration; gold doped silicon junction CLASS CODES: A7125 (Nonlocalized single-particle electronic states); A7220 (Electrical conductivity phenomena in semiconductors and insulators); A7340 (Electrical and electronic properties of interfaces); B2530B (Semiconductor junctions) --------------------------------------------------------------------------- Record: 76 RECORD NO.: 174724 INSPEC Abstract No: A70053839; B70031263 AUTHOR: Sah, C.T.; Forbes, L.; Rosier, L.L.; Tasch, A.F., Jr. CORP SOURCE: Univ. Illinois, Urbana, IL, USA TITLE: Thermal and optical emission and capture rates and cross sections of electrons and holes at imperfection centers in semiconductors from photo and dark junction current and capacitance experiments SOURCE: Solid-State Electronics, vol.13, no.6, p. 759-88 ISSN: 0038-1101 CODEN: SSELA5 PLACE OF PUBL: UK LANGUAGE: English YEAR: June 1970 ABSTRACT: Photo and dark current and capacitance transient experiments are described which can provide highly accurate and unique data of the electronic properties of impurity centers in semiconductors such as energy level, multiplicity of charge state, thermal and optical emission rates, thermal capture rates, thermal and optical cross sections and the dependences of the rates and cross sections on sample temperature, static electric field and photon energy. These experiments are grouped into four categories in the discussion according to the temperature (below and above freeze-out or negligible and finite thermal rates) and presence or absence of optical excitation at the impurity center (19 Refs.) DESCRIPTORS: electrical conductivity of solids; impurity electron states and effects; photoconductivity; semiconductor materials; semiconductors; thermoelectricity CLASS CODES: A7220P (Thermoelectric effects (semiconductors/insulators)); A7240 (Photoconduction and photovoltaic effects; photodielectric effects); B2550 (Semiconductor device technology) --------------------------------------------------------------------------- Record: 77 RECORD NO.: 108817 INSPEC Abstract No: B70010580 AUTHOR: Forbes, L.; Chih Tang Sah TITLE: Application of the distributed equilibrium equivalent circuit model to semiconductor junctions SOURCE: IEEE Transactions on Electron Devices, vol.ed-16, no.12, p. 1036-41 ISSN: 0018-9383 CODEN: IETDAI PLACE OF PUBL: USA LANGUAGE: English YEAR: Dec. 1969 ABSTRACT: The small-signal equivalent circuits for a p-n junction at equilibrium and the MOS capacitor in the inversion range are derived from the general transmission line model. Detailed calculations are made to obtain the semiconductor admittance as a function of frequency for a gold-doped n-type silicon substrate. The transmission-line model provides the desired distributed time constant observed in experimental data of admittance versus frequency. A simple model illustrates how the l.f. junction capacitance depends on the position of the deep level recombination centre in the band gap and the ratio of the hole and electron emission rates. Experimental results on gold-doped silicon junctions are analyzed in terms of the theoretical model (19 Refs.) DESCRIPTORS: equivalent circuits; semiconductor device models; semiconductor junctions CLASS CODES: B2530B (Semiconductor junctions); B2560H (Junction and barrier diodes); B2560B (Semiconductor device modelling and equivalent circuits) --------------------------------------------------------------------------- Record: 78 RECORD NO.: 108595 INSPEC Abstract No: A70018284; B70010326 AUTHOR: Sah, C.T.; Rosier, L.L.; Forbes, L. CORP SOURCE: Univ. Illinois, Urbana, IL, USA TITLE: Direct observation of the multiplicity of impurity charge states in semiconductors from low-temperature high-frequency photocapacitance SOURCE: Applied Physics Letters, vol.15, no.10, p. 316-18 ISSN: 0003-6951 CODEN: APPLAB PLACE OF PUBL: USA LANGUAGE: English YEAR: 15 Nov. 1969 ABSTRACT: A simple method provides a direct and reliable observation by recording the high-frequency photocapacitance changes in a reverse-biased p-n junction at a low temperature during monochromatic illuminations at different wavelengths. The photon energy is first chosen so that it is above the threshold of exciting the next electron. After the capacitance change is completed, the photon energy is increased to the next range to excite the second trapped electron into the conduction band. The equality of the change of the squared capacitance during these two illumination periods then implies a multiplicity of three of the charge state. The procedure may be repeated for more than three charge states (11 Refs.) DESCRIPTORS: crystal impurities; impurity electron states and effects; semiconductor defects; semiconductors CLASS CODES: A0750 (Electrical instruments and techniques); A7155 (Impurity and defect levels); A7220 (Electrical conductivity phenomena in semiconductors and insulators) --------------------------------------------------------------------------- Record: 79 RECORD NO.: 101462 INSPEC Abstract No: A70012129; B70007428 AUTHOR: sah, C.T.; Rosier, L.L.; Forbes, L. TITLE: Low-temperature high-frequency capacitance measurements of deep- and shallow-level impurity center concentrations SOURCE: Applied Physics Letters, vol.15, no.6, p. 161-3 ISSN: 0003-6951 CODEN: APPLAB PLACE OF PUBL: USA LANGUAGE: English YEAR: 15 Sept. 1969 ABSTRACT: A simple method is proposed and demonstrated for the determination of a minute amount of deep-level impurities in the transition region of p-n junctions from the high- frequency capacitance change when the junction temperature is lowered from room temperature to 77 degrees K and the junction bias is switched to zero and back to the large reverse bias to set the charge trapped at these centers to the equilibrium value. Sensitivity of 10/sup 11/ atoms/cm/sup 3/ and 10/sup 5/ total atoms in the depletion layer is demonstrated in junction gettered by phosphorus glass. Examples are also given for Ni- and Au-doped silicon diodes and transistors DESCRIPTORS: capacitance measurement; p-n junctions; semiconductor diodes; semiconductor junctions CLASS CODES: A7220 (Electrical conductivity phenomena in semiconductors and insulators); A7340 (Electrical and electronic properties of interfaces); B2530B (Semiconductor junctions); B2560H (Junction and barrier diodes) --------------------------------------------------------------------------- Record: 80 RECORD NO.: 86538 INSPEC Abstract No: A70004709 AUTHOR: Sah, C.T.; Forbes, L.; Rosier, L.I.; Tasch, A.F., Jr.; Tole, A.B. CORP SOURCE: Univ. Illinois, Urbana, IL, USA TITLE: Thermal emission rates of carriers at gold centers in silicon SOURCE: Applied Physics Letters, vol.15, no.5, p. 145-8 ISSN: 0003-6951 CODEN: APPLAB PLACE OF PUBL: USA LANGUAGE: English YEAR: 1 Sept. 1969 ABSTRACT: Thermal emission rates of electrons and holes at the gold- acceptor center (E/sub C/-E/sub Au-/=550 mV) and of holes at the gold-donor center (E/sub Au+/-E/sub V/=350 mV) are measured using the dark current, dark capacitance, and photocapacitance transient methods. About ten decades of the electron emission rate and eight decades of the hole emission rates are obtained in the temperature range of -160 to +100 degrees C. The data correspond to electric fields of 10/sup 4/ and 10/sup 5/ V/cm maximum field in the p-n junction (10 Refs.) DESCRIPTORS: elemental semiconductors; gold; silicon CLASS CODES: A7220 (Electrical conductivity phenomena in semiconductors and insulators); A7280C (Conductivity of elemental semiconductors) _______________________________________________________________________ Record: 81 RECORD NO.: 66500 INSPEC Abstract No: A69039636; B69020243 AUTHOR: Sah, C.T.; Forbes, L.; Rosier, L.L.; Tasch, A.F., Jr. CORP SOURCE: Univ. Illinois, Urbana, IL, USA TITLE: Thermal and optical emission rates and cross sections from the impurity photocurrent and photocapacitance methods SOURCE: Solid State Commun. (USA), Solid State Communications, vol.7, no.11, p. 5-5: 1 pp. ISSN: 0038-1098 CODEN: SSCOA4 PLACE OF PUBL: USA LANGUAGE: English CONF TITLE: Proceedings of the third international conference on photoconductivity CONF LOCATION: Stanford, CA, USA; 12-25 Aug. 1969 YEAR: June 1969 ABSTRACT: Abstract only given substantially as follows:- Previous methods of measuring the carrier emission rate and capture cross sections at defect centers in semiconductors suffer from two sources of error: nonexponential decay law and uncertainty in the defect concentration. These can be removed using a reverse biased p-n junction. The impurity photovoltaic method previously proposed is described in detail. Other new methods of photocapacitance and dark junction current transients under square wave illumination and/or junction voltage will be described which compliment the impurity photovoltaic method. These methods are illustrated using the experimental results of gold acceptor and donor centers in silicon. Ten decades of electron and hole emission rates at these two gold centers from -100 degrees C to +100 degrees C are obtained using six sets of experiments involving both transient and steady state photo and dark junction current and capacitance measurements DESCRIPTORS: carrier mobility; crystal electron states; electrical conductivity of solids; elemental semiconductors; gold; impurity electron states and effects; photoconductivity; semiconductor defects; semiconductor materials; semiconductors CLASS CODES: A7155 (Impurity and defect levels); A7220 (Electrical conductivity phenomena in semiconductors and insulators); A7240 (Photoconduction and photovoltaic effects; photodielectric effects)