摘要:

Magnetron ion etching (MIE) of InP has been studied using methane and hydrogen. These results of the first study are compared with those obtained with reactive ion etching (RIE) using the same gases in the same machine but without the magnet. The advantages of the MIE system demonstrated here include etching rates about three to four times higher and a lower degree of acceptor passivation (reduction in carrier concentration of etched surface), a low self‐bias of between 70–200 V, and a resulting etched surface which is very smooth. Moreover, it is found that RIE and MIE give very similar degree of passivation depths, provided sample temperature during etching does not exceed 60 °C. However, MIE is favored because of higher etch rates. The degree of passivation in the MIE also depends on the percentage of methane used in the process. Anisotropic etching of InP with the MIE can be achieved under certain conditions of high pressure, but in conjunction with reduced etch rate and degraded surface morphology.

ISSN:0734-211X    

DOI:10.1116/1.585379

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

The use of reflection high‐energy electron diffraction oscillations to obtain lattice‐matched In0.53Ga0.47As and In0.52Al0.48As on InP is described. This method has also been extended to the growth of strained InyGa1−yAs and InxAl1−xAs on InP as well as that of quaternary In1−x−yGaxAlyAs compositions, lattice‐matched in InP.

ISSN:0734-211X    

DOI:10.1116/1.585380

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

We present the first comprehensive investigation of the bulk properties, both optical and structural, of cubic GaN as grown by plasma‐assisted molecular‐beam epitaxy on vicinal (100) GaAs substrates. X‐ray measurements determined the crystal structure of GaN/GaAs to be cubic with a lattice constant of 4.5 Å. High resolution transmission electron microscopy revealed a high density of planar defects propagating along the GaN {111} planes. The majority of the defects originated from disordered regions at the GaN/GaAs interface. The optical properties of the films were investigated by cathodoluminescence which revealed a broad midgap peak as well as several sharp emission peaks just below the expected band gap. The data imply that the room temperature band gap of cubic GaN is approximately 3.45 eV.

ISSN:0734-211X    

DOI:10.1116/1.585381

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

Device characteristics of AlGaAs/GaAs heterostructure field effect transistors fabricated by molecular‐beam epitaxial growth are related to the condition of the substrate‐epitaxial layer interface. The presence of carbon on the GaAs wafer surface prior to growth has been found to produce ap‐type, conducting interfacial region. We demonstrate that the concentration of carbon on the wafer surface can be significantly reduced by exposing the wafers to ultraviolet radiation. Depletion‐ and enhancement‐mode device transfer characteristics and transconductance curves have been obtained on heterostructure wafers that were subjected to an ultraviolet‐ozone surface preparation. A comparison of these results with the device properties of wafers receiving a standard cleaning procedure is presented. A model describing the interaction between the interfacialp‐type region and the two‐dimensional electron gas channel is also included.

ISSN:0734-211X    

DOI:10.1116/1.585382

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

We have developed a novel treatment of ZnSe substrates for homoepitaxy using dry etching with a BCl3plasma. The dry‐etched substrates exhibited mirror‐like morphology even after 10‐μm etching in thickness to remove polishing damage, and the quality of its surface was remarkably improved. Subsequent thermal etching of ZnSe was found by reflection high‐energy electron diffraction observation to be valid in the temperature range from 440 to 650 °C. Highest‐quality ZnSe homoepitaxial layer has been obtained by growth on the substrate etched at the BCl3pressure of 60 mTorr. Crystallinity of the layer was as good as that of the dry‐etched substrate. Low‐temperature optical analysis indicated the layer to be high purity and to be free from in‐plane biaxial strain.

ISSN:0734-211X    

DOI:10.1116/1.585383

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

The photographic behavior of unsensitized evaporated layers of As2S3exposed by x rays in the spectral region of 2–7 nm is studied. The photographic sensitivity is found to be 500–600 mJ/cm2and the limits of photographic treatment are determined. It is concluded that the layers could be discussed as promising material for x‐ray microlithography.

ISSN:0734-211X    

DOI:10.1116/1.585384

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

Millisecond annealing using a dual electron beam annealer has been performed on 4 in. wafers for the activation of arsenic and boron difluoride source and drain implants as part of a complementary metal–oxide semiconductor process. Gross wafer distortion has been avoided by the use of a high background temperature and a synthesized line scan. Measurements of electrical activation of the implanted dopant indicates no metastable highly active phases, but activation to electrical solubility limits of longer lamp anneals performed at the same temperature. Measurements on transistors fabricated using single scan millisecond annealing show annealing cycle induced interface damage no worse than that seen in isothermal lamp anneals.

ISSN:0734-211X    

DOI:10.1116/1.585385

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

A s_mall s_ource/d_rain c_ontact (SSDC) formation technology has been developed. In the SSDC structure, self‐aligned contacts to small source/drain (S/D) regions can be formed without any contact holes because a local TiSi2interconnect which extends over isolation fields is directly combined with the whole S/D surface area. It is essential in the SSDC process that the local TiSi2interconnects are formed from a solid phase reaction of the amorphous‐Si (sputter deposited)/Ti (sputter deposited) bilayer containing a low oxygen concentration. The local TiSi2interconnect is thermally stable up to 900 °C furnace annealing. This thermal stability allows one to use the TiSi2layer as a solid phase diffusion source for the S/D formation. Consequently submicronn‐channel metal–oxide–semiconductor field effect transistors with the SSDC structure were fabricated and tested, with a physical gate size of 0.42 μm(length)×2.0 μm(width), and the S/D area was shrunk down to 0.4 μm(length)×2.0 μm(width). The maximum linear transconductance was ∼31 mS/mm.

ISSN:0734-211X    

DOI:10.1116/1.585386

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

In order to provide data needed in the investigation and modeling of stress voiding in integrated circuit metallizations, stress and stress relaxation in Al/Si/Cu alloys and common dielectrics were studied as a function of storage temperature and deposition conditions. It was found that the room‐temperature tensile stress in Al/Si/Cu increases with increasing substrate bias and deposition temperature, and that the isothermal relaxation rate upon cooling from 400 °C is sharply dependent on temperature. The activation energy for the relaxation process was found to be 0.39 eV above 130 °C and about 0.08 eV at lower temperatures. For insulating layers deposited with plasma‐enhanced chemical‐vapor deposition techniques, strong correlations were found among stress, density, hydrogen content, deposition temperature, and film composition (oxides, nitrides, and several intermediate oxynitrides), with the highest levels of compressive stress (near 1 GPa) being measured in nitride films deposited at 300 °C. These films, as well as phosphorus‐doped glasses used as capping/protection layers, were found to undergo structural changes upon post‐deposition thermal cycling which affected stress levels.

ISSN:0734-211X    

DOI:10.1116/1.585387

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

A novel Si‐sample cleaning method is described. This low‐temperature process uses ultraviolet (UV) radiation and an ozone beam to remove carbonaceous components from the native oxide ofas‐receivedSi samples. Because the cleaning process is implemented as an ultrahigh vacuum (UHV) process in a UHV process chamber, the sample does not need to be reexposed to atmospheric conditions between the carbon removal and the desorption of the native oxide, which results in very low contamination levels. The efficiency of this carbon removal‐method is determined.

ISSN:0734-211X    

DOI:10.1116/1.585388

出版商:American Vacuum Society    

年代:1991

数据来源: AIP