A. Schlachetzki

Doping Profile Analysis in Si by Electrochemical Capacitance‐Voltage Measurements

The electrochemical capacitance-voltage (ECV) technique was used to measure the carrier concentration profiles in Si. Using the conventional parallel-equivalent circuit model of the Schottky junction to describe the electrolyte-silicon barrier we found excellent agreement between ECV and four-point probe analyses within ±10 to 20% for bulk Si uniformly doped p- and n-type from 10 12 to 10 18 cm -3 . In this concentration range accuracy limits are determined mainly by the precise measurement of the area of the electrolyte-Si contact. For the anodic etching of Si, a constant effective dissolution valence of z=3.7 was used throughout the measurements. Investigations with isotype and anisotype doping transitions were performed employing ECV and other profiling techniques for comparison

Electron-concentration dependence of absorption and refraction in n-In 0.53 Ga 0.47 As near the band-edge

The optical constants of InGaAs were determined as a function of electron concentration in the range from 1015 to 2 × 1019 cm−3 by reflectance- and transmission-spectroscopy. A pronounced shift of the fundamental absorption edge toward shorter wavelengths with increasing doping concentration was found. The experimental results can be satisfactorily explained by band-filling and band-gap shrinkage.

Effect of III/V-Compound Epitaxy on Si Metal-Oxide-Semiconductor Circuits

Several approaches to the heteroepitaxial growth of InP on (100)Si employing an electrochemically etched Si mesa, SiO2 masks, and a maskless procedure were investigated with the objective of achieving area-selective InP integration into Si metal-oxide-semiconductor (Si-MOS) technology. Maskless InP/Si device layer growth by metal-organic vapour-phase epitaxy with good selectivity on a structured InP buffer layer, surrounded by oxide, was achieved. Undesired InP depositions were removed with an SiO2 emulsion, spun on prior to InP growth. To study the effects on the Si-based electronics, p-metal-oxide-semiconductor field-effect tansistors (MOSFETs) were exposed to the various stages of the heteroepitaxial InP growth process. We have studied the influence of hydride atmospheres and thermal anneals on their electrical performance. A standard InP-on-(100)Si growth procedure was found to be acceptable for the MOS components, as demonstrated by a Schmitt-trigger laser-diode driver circuit.

InGaAs quantum wires and wells on V-grooved InP substrates

We report on the fabrication and characterization of In1−xGaxAs quantum structures on V-grooved InP substrates grown by metalorganic vapor phase epitaxy. The geometry of the quantum wells and wires was determined by scanning-electron microscopy and atomic-force microscopy. We optimized the InP buffer-layer thickness in order to obtain narrow quantum wires. The optical properties were studied by photoluminescence (PL) spectroscopy. The PL peaks of the different quantum structures can be identified by a self-aligned masking process. The interpretation of the PL measurements was verified by means of cathodoluminescence measurements with high spatial resolution. Transition energies were evaluated from the geometry of the quantum wells and quantum wires. The composition of the InGaAs was used as a parameter for the calculations. By comparison of the measured transition energies with the evaluated ones we determined the Ga content of the quantum structures. We found the quantum wires nearly lattice matched to t...

High-speed InP-based resonant tunneling diode on silicon substrate

A technology for high speed and high performance III-V semiconductor devices on silicon substrate has been developed. It consists of an InP-on-Si quasi-substrate exhibiting an XRD FWHM as low as 86 arcsec, followed by a low-temperature (370/spl deg/C) grown InAlAs layer. The surface roughness is reduced to 1.9 nm along with an almost complete elimination of surface defects. The applicability is experimentally verified for InP-based resonant tunneling diodes exhibiting a speed index of 32 ps/V indicating a potentially low-cost technology for high functionality circuits operating above 10 Gb/s.

A low-frequency micromechanical resonant vibration sensor for wear monitoring

Abstract A micromechanical resonant vibration sensor (MRVS) is presented with a geometrical structure that is designed for the detection of vibrations in the low-frequency range. The MRVS is distinguished from conventional piezoelectric and micromechanical acceleration sensors by the utilization of the resonance effect. The signal-to-noise ratio increases significantly when the sensor is excited with the designed frequencies. The vibrational properties of the MRVS have been investigated in the laboratory. Examples of the sensor response to different vibrational sources are analysed under industrial conditions. The capability of the sensor principle for wear monitoring is discussed.

Anodic Dissolution during Electrochemical Carrier‐Concentration Profiling of Silicon

The anodic dissolution process of silicon in aqueous ammonium-bifuoridesolution during electrochemical carrier-concentration profiling has been investigated for samples of various crystal orientation as well as dopant type and concentration. The effective dissolution valence and the surface roughness of the etched crater bottom was measured in dependence on the electrode potential, the dissolution current density, the electrolyte concentration, and, as necessary for the anodic dissolution of n-type material, the illumination intensity

Ultrasmooth V‐Grooves in InP by Two‐Step Wet Chemical Etching

A two-step wet chemical etching process using HBr and HBr:K 2 Cr 2 O 7 was developed in order to fabricate high-quality V-grooves in InP (100) wafers. A 40 nm titanium film, which was patterned by conventional photolithography and lift-off, was used as the etching mask. The (111)A sidewalls are mirrorlike with an arithmetic average roughness of less than 0.4 nm. The tip radius of the V-grooves is approximately 7 nm. Both values were determined by atomic force microscopy.

Antiphase-domain-free InP on (100) Si

We show that antiphase-domain-free InP can be grown by means of low-pressure metalorganic-vapor-phase epitaxy (LP-MOVPE) on exactly (100)-oriented Si by appropriate choice of growth parameters. A simple detection scheme for antiphase domains (APD) in InP is presented. The most likely reason for the absence of APDs on the InP surface is their annihilation during the growth.

Laser-action in V-groove-shaped InGaAs-InP single quantum wires

We report on the realization of a V-groove-shaped single quantum wire (QWR) laser in the material system InGaAsP-InP. First, we discuss a new laser concept that makes use of a semi-insulating (s.i.) current-blocking layer and InGaAsP wave-guiding layers. Simulations demonstrate the concentration of both the current as well as the optical field in the active region. We developed a two-step wet-chemical etching process, to form high-quality V-grooves into a layer stack consisting of InP and InGaAsP. By employing anisotropic wet-chemical etching and anisotropic metal-organic vapor-phase epitaxial (MOVPE) growth, we demonstrate the feasibility of this concept. We show laser action originating from a single InGaAs QWR realized in this concept. The source of a second laser line measured with electroluminescence (EL) spectroscopy is discussed.