摘要:

Photochemical etching of laser‐produced defect centers inn‐ andp‐type Al(Ga,As) heterostructures has been investigated. Inn‐type (Al,Ga)As a decrease of etch rate in the processed zone is observed leading to etch hillocks whereas inp‐type (Al,Ga)As a mesalike structure is formed: the center of the processed zone, 0.5 &mgr;m wide, shows the same etch rate as the unprocessed material whereas the adjacent regions, 10 &mgr;m wide, etch faster. From this etching behavior the following conclusions are made. (1) The laser processing introduces two different defects. DefectAis located in the center of the processed zone, defectBin the adjacent regions. (2) TypeAdefect is inactive in etching ofp‐type material. (3) Combined with luminescence data we assign for this center an energy level 100 meV above the valence band. (4) DefectBis a deep level located in the midgap region.

ISSN:0003-6951    

DOI:10.1063/1.95246

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The electrical characteristics of Schottky diodes fabricated on silicon surfaces subject to low‐energy (10 keV) argon ion implantation have been studied as a function of Ar+ion dose. Significant changes in electrical characteristics are seen for ion doses as low as 5×1011cm−2, well below the amorphization threshold dose for Si. In conjunction with the ion energy threshold established earlier for Si surface damage effects (∼25 eV), these results outline fundamental limits on the effect of ion‐assisted dry etching processes on Si surface barriers.

ISSN:0003-6951    

DOI:10.1063/1.95247

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Investigated are the current‐voltage characteristics of metal (Au, Mg)/B‐doped hydrogenated amorphous silicon (a‐Si:H)/crystalline silicon (n+,p+) diodes for various doping levels of B ina‐Si:H. From junction studies we determine the conduction type of B‐dopeda‐Si:H on the basis of ‘‘dominant’’ carrier concentration, and find that thep‐ntransition occurs at B2H6/SiH4∼10−6although the conductivity minimum appears at B2H6/SiH4∼10−4.

ISSN:0003-6951    

DOI:10.1063/1.95248

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Ion implantation forn‐type doping of high‐density (CH)xfilms was studied experimentally. Apparent doping effects were observed in those films implanted with relatively low‐energy (12 keV) sodium ions. Current‐voltage characteristics of ap‐njunction produced between the implanted and original (p‐type) regions in a film exhibited a rectifying behavior for over 37 days. The improved stability in air was also observed. Doping by ion implantation is potentially useful to increase the life span of (CH)xdevices up to the point of practical use.

ISSN:0003-6951    

DOI:10.1063/1.95249

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report that the distribution of localized density of statesg(E) for hydrogenated amorphous silicon can be estimated by the electrophotographic (xerographic) method. The density of states near midgap can be evaluated to be about 1×1016 cm−3 eV−1for undoped films. The general trend and the shape ofg(E) are similar to those obtained by the deep level transient spectroscopy and the photothermal deflection spectroscopy.

ISSN:0003-6951    

DOI:10.1063/1.95250

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

In this letter we report the first growth of diluted magnetic semiconductor superlattices. Bright and dark field transmission electron microscopy images confirm that the superlattices consist of distinct periodic layers of uniform composition and thickness. The photoluminescence spectra of the superlattices are found to be over three orders of magnitude more intense when compared to uniform thin films (and bulk samples) grown under similar conditions. The reason for this large increase is not clearly understood but this effect may have important consequences for future applications of these novel materials in optoelectronic devices.

ISSN:0003-6951    

DOI:10.1063/1.95223

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Indium phosphide photoelectrodes have been studiedinsituusing electrochemical photocapacitance spectroscopy. The observed photocapacitance spectra were a strong function of electrode surface conditions. The photoionization energies of the chemically induced surface states correlated well with previously reported values determined by surface photovoltage spectroscopy. The chemical treatment of the InP electrode surface with Co and Pt reduced the concentration of deep level interface states near the valence band and introduced a new state atEv+1.2 eV.

ISSN:0003-6951    

DOI:10.1063/1.95251

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Titanium disilicide films were sputter deposited from a composite TiSi2.1target on ⟨111⟩ bare silicon wafers both at room temperature and at 600 °C. The room temperature as‐deposited films require a 900 °C sintering step to reduce their resistivity. On the other hand, the as‐deposited 600 °C films are fully reacted, polycrystalline, have no oxygen contamination, large grain sizes, and are oxidation resistant. Further annealing of these films at 900 °C produces no changes in their crystal structure, composition, resistivity, or grain size.

ISSN:0003-6951    

DOI:10.1063/1.95252

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

An array of field‐effect transistors fabricated by direct ion implantation on a liquid‐encapsulated‐Czochralski (LEC) In0.003Ga0.997As wafer exhibits greater uniformity of threshold voltage than arrays on similarly processed conventional LEC GaAs wafers. However, there is no correlation between a transistor’s threshold voltage and its proximity to a dislocation for either In‐alloyed or conventional LEC GaAs substrates. An observed correlation of threshold voltage with local dislocation density for GaAs substrates can lead to the erroneous inference that threshold voltage is affected by dislocation proximity.

ISSN:0003-6951    

DOI:10.1063/1.95210

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

When the molecular‐beam epitaxial (MBE) growth of GaAs or (Al,Ga)As is interrupted and the surface is exposed to air for other kinds of processing, a high concentration (>2×1011cm−2) of surface defects tends to form which will show up as highly detrimental interface defects if the MBE growth is subsequently resumed. We show that the surface can be protected by a thin epitaxial layer of InAs, which is highly resistant to many kinds of processing steps, and which can be thermally removed before resumption of growth, leading to an ‘‘invisible’’ restart interface.

ISSN:0003-6951    

DOI:10.1063/1.95211

出版商:AIP    

年代:1984

数据来源: AIP