P-type Diodes Research Articles

Barrier Height of Fe Contacts to Si

Measurements of electron and hole barriers of junctions between evaporated Fe films and Si both of p- and n-type are reported. From a study of the forward I-V characteristics, we obtain a value for the hole barrier of ϕBh ≈ 0.50 ± 0.03 eV using the p-type diodes and a value of ϕBe ≈ 0.62 ± 0.03 eV using the n-type diodes. The sum of the barrier heights comes close to the bandgap, as expected.

Enhancement of effective barrier height in Ti-silicon Schottky diode using low-energy ion implantation

Increasing the effective barrier height in a Ti-p-type silicon Schottky diode has been achieved by means of low-energy ion implantation to introduce a thin inversion layer on silicon substrate. It is shown theoretically that effective barrier height equal to the energy bandgap can be obtained in such structure if the thickness and dopant density of the implanted layer are properly chosen. Experimental results for several titanium (Ti) on phosphorus implanted p-type silicon Schottky diodes show that effective barrier heights were increased from 0.6 eV for the Ti-p Si Schottky diode to 0.96 eV for a Ti-n-p-Si Schottky diode with a phosphorus-implanted layer thickness of 400 A and dose of 1.26 × 1012cm-2. Good agreement is obtained between the calculated and the measured barrier height for several Ti-n-p silicon Schottky diodes.

Measurement of the minority-carrier transport parameters in heavily doped silicon

A new method for simultaneous measurement of bandgap narrowing and diffusion length in a heavily doped n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> substrate is proposed. The method uses planar test pattern at the front side of the substrate to determine the hole minority-carrier current injected from a p-type emitter and diodes at the rear side to measure diffusion lengths. The method can be generalized such that the minority-carrier diffusion constant can be estimated and the use of extrapolated literature data can be avoided. Results of measured values of bandgap narrowing and diffusion length versus impurity concentration are given for n-type material.

Transient high level majority and minority carrier photocurrents in p-type silicon Schottky barrier diodes—I comparison with analytic theory

Transient high level majority and minority carrier photocurrents in p-type silicon Schottky barrier diodes—I comparison with analytic theory

Photovoltage spectra of metal–silicon (p-Type) diodes near the indirect absorption edge of silicon

Photovoltage spectra of Al–, Hf– and Yb–Si(p) Schottky barrier diodes are measured at 300 and 100 K in the photon energy range from 0.8 to 1.3 eV. A detailed analysis of the spectra is made where the following processes are considered: photoemission from metal to semiconductor, band-to-band excitations, and excitations from deep impurity levels in semiconductor. Indirect exciton transitions accompanied both by absorption and by emission of one or two TA, TO, and 0 phonons were observed. The phonon energies, the exciton binding energy, and the shape of the spectrum are compared with earlier experimental results and theory. Measurements with different reverse bias voltages and the analysis of the indirect band-to-band transitions essentially facilitate the determination of the barrier height. Es werden Photospannungspektren von Al–, Hf– und Yb–p-Typ Si Schottky-Dioden bei 300 und 100 K im Photonenenergiebereich von 0,8 bis 1,3 eV gemessen. Eine detaillierte Analyse wird durchgefuhrt, in der die Beitrage der Photoemission vom Metall in den Halbleiter, der Interbandubergange und der Ubergange aus tiefen Storstellen im Halbleiter in Betracht gezogen wurden. Indirekte Exziton-Ubergange werden beobachtet, die sowohl von Absorption als auch Emission von ein oder zwei TA-, TO- und 0-Phononen begleitet werden. Die Phononenenergien, die Exzitonenbindungsenergie und die Form des Spektrums werden mit fruheren experimentellen Resultaten und der Theorie verglichen. Messungen bei verschiedenen Spannungen in Sperrichtung und die Analyse der indirekten Interbandubergange erleichtern wesentlich die Bestimmung der Barrierenhohe.

Microstrip Varactor-Tuned Millimeter-Wave IMPATT Diode Oscillators

Varactor-tuned millimeter-wave IMPATT diode oscillators in microstrip form using chip-mounted diodes are described. A nearly level output power of 28 /spl plusmn/ 8 mW was achieved over a 6-GHz tuning range. Tunable bandwidths as high as 8 GHz with 6-26 mW of power were obtained from a single source. P-type epitaxial silicon IMPATT diodes were used for both the active device and the tuning varactor functions.

Calculation of p-type GaAs IMPATT admittance

The unequal ionization rates reported for holes and electrons in GaAs have been used to calculate the small-signal admittance for a complimentary p-type IMPATT diode. For the uniformly doped n and p device structures considered, the p-type structure is found to have significantly increased negative conductance.

Effect of heavier doped junction side on efficiency of Si IMPATT diodes

For n- and p-type Si IMPATT diodes, the effect of the doping profile of the heavier doped junction side was calculated in terms of the dc-to-RF efficiency. In p-type diodes, the electric field existing within this region leads to a decrease in efficiency. This effect is assumed to be one reason why the theoretically expected high efficiencies of these diodes have not been obtained experimentally.

Effects of ionization rates on silicon IMPATT devices

The effects of ionization rates of electrons and holes on the properties of silicon IMPATT devices are presented. Both p-type and n-type silicon diodes are considered. Small- and large-signal results are given for typical X-band devices.

Performance of P-type epitaxial silicon millimeter-wave IMPATT diodes

A series of p-type IMPATT diodes (p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> pn <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ) have been fabricated from epitaxially grown silicon for operation as oscillators at K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</inf> -band frequencies. A maximum CW output power level of 700 mW at 29.6 GHz, a maximum conversion efficiency of 10.9 percent, and a minimum FM noise parameter, M, of 25 dB have been measured on this series of p-type diodes. A diode oscillating in a variable height radial disk cavity was frequency tuned from 27.5 to 40 GHz, covering the entire K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</inf> -band, with a 1.4 dB power variation over the tuning range. The minimum CW output power of this tunable oscillator was 360 mW at 6.5 percent efficiency.

I band (8-10 GHz) TRAPATT-diode sources

The feasibility of a high-pulsed-power I band source using both n-type and p-type TRAPATT diodes has been demonstrated. Deep-diffused n-type diodes have generated more than 100 W in the I band.

Titanium-silicon Schottky barrier diodes

Schottky barriers have been formed by vacuum evaporation of titanium onto chemically cleaned n- and p-type silicon. The barrier heights of the contacts were found to 0.50 and 0.61 eV for n- and p-type barriers, respectively. The barrier heights were determined from measurements of the 1 C 2 vs. V characteristics, the reverse saturation current density, and the activation energy of the reverse current. The effects of fabrication technique on diode properties are discussed. It is found that p-type diodes can be fabricated using standard oxide passivation techniques, without severe degradation of most diode properties; n-type diodes are severely degraded by the presence of silicon dioxide at the periphery of the diode, but this problem can be completely eliminated by the use of a diffused p-type ‘guard-ring’. Noise measurements are also presented for the p-type oxide-passivated diodes and for the n-type ‘guard-ring’ diodes; these diodes are found to have essentially ideal noise behavior above a few kHz.

Further evidence for the barrier lowering due to the mechanical pressure on p-type germanium point contact diode

Minority carrier injection ratio of the point contact diode decreases with the increase in the mechanical pressure exerted on the point contact in p-type Ge. The result seems to serve as an evidence for the barrier lowering effect which also causes the pronounced sensitivity in the pressure effect of the reverse current.

Trap Levels in Gallium Arsenide

The effect of illumination on the capacitance of n- and p-type GaAs Schottky barrier diodes has been measured at 77°K. Capacitance change is observed in the photon energy range of (0.7 eV–1.45 eV) for the n-type diode and in the range of (0.5 eV–1.45 eV) for the p-type diode. This effect is explained in terms of the photoexcitation of traps in the space charge layer. It is found that two different kinds of traps are present in both n- and p-type GaAs, one being located at about 0.7 eV and another at about 0.95 eV, below the conduction band edge. The traps found in the present experiment are probably identical with those found in semi-insulating GaAs crystals.

Evaluation of Surface States at Si–SiO2 Interface from the Characteristics of P-Type MOS Diodes

Evaluation of Surface States at Si–SiO2 Interface from the Characteristics of P-Type MOS Diodes