摘要:

The secondary defect annihilation titanium silicidation in SixGe1−xlayers, formed by high dose Ge implantation in (100) silicon, has been studied systematically as a function of the Ge fluence, implantation energy, and TiSi2thickness. Rutherford backscattering spectrometry and transmission electron microscopy have been used to investigate the damaged SixGe1−xlayer recovery and to monitor the germanium diffusion and reaction during the silicidation. For the highest fluence of 3×1016Ge/cm2(≊15 at. % Ge) it is found that nearly a complete annihilation of the secondary defects can be achieved after the first low‐temperature silicidation step. After a second high‐temperature silicidation step all residual defects have been removed. For fluences lower than 3×1016Ge/cm2a complete recovery is already obtained after the first silicidation step. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114846

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

High‐quality TiN films were deposited in an electron cyclotron resonance (ECR) plasma process at low substrate temperatures between 100 and 450 °C using tetra‐isopropoxide titanium (TIPT) {Ti[OCH(CH3)2]4} as precursor. TIPT was introduced into the downstream region of an ECR nitrogen or ammonia plasma. The electrical properties of the gold colored TiN layers (100–400 &mgr;&OHgr; cm) depend on the deposition rate and the substrate temperature. Despite the use of an oxygen containing titanium precursor the oxygen content in the TiN was found to be ≤2 at.%. The measured resistivities and the purity of the TiN films indicate a selective cleavage of the isopropoxide ligand in the ECR downstream plasma. The films were characterized by resistivity measurements and secondary ion mass spectrometry. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114847

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

High‐resolution electron energy loss spectroscopy, low‐energy electron diffraction, and quadrupole mass spectrometer have been employed to study the effect of atomic hydrogen on the acetylene saturated preadsorbed Si(100)(2×1) surface at room temperature. It is evident that the atomic hydrogen has a strong effect on the adsorbed C2H2and the change of the underlying surface structure of Si. The experimental results show that CH and CH2radicals coexist on the Si surface after the dosing of atomic hydrogen; meanwhile, the surface structure changes from Si(2×1) to a dominant of (1×1). These results indicate that the atomic hydrogen can open C=C double bonds and change them into C–C single bonds, transfer the adsorbed C2H2to C2Hx(x=3,4) and break the underlying Si–Si dimer, but it cannot break the C–C bond intensively. Some C4species have been formed during the dosing with atomic hydrogen. It may be the result of atomic hydrogen abstraction from C2Hxwhich leads to carbon catenation between two adjacent CC dimers. The formed C4is stable on Si(100) surfaces up to 1100 K and can be expected to host diamond nucleation. ©1995 American Institute of Physics.[S0003‐6951(95)04246‐X]

ISSN:0003-6951    

DOI:10.1063/1.114848

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The thermal diffusivity of &ggr;‐alumina is determined by the photoacoustic method. The method is calibrated by determining the thermal diffusivity of copper and aluminum. The effect of the chemisorbed hydroxyl groups on thermal diffusivity is studied by degassing the sample at different temperatures. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114818

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We have found that seconds of 100 mW Ar laser exposure produces more than 100 times an increase in infrared photoluminescence (PL) intensity in thin‐film polycrystalline silicon (poly‐Si). The change of PL intensity on laser exposed film areas (minimum spot size of 20 &mgr;m) and the variation in film surface morphology measured by atomic force microscope are compared. The effect of PL enhancement strongly correlates to two distinctive processes: (a) the increase of a grain size due to poly‐Si recrystallization, and (b) the oxygen incorporation into the film from glass or quartz substrates or/and from ambient gas. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114819

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Growth of ZnSe/MgS strained‐layer superlattices (SLSs) has been carried out by molecular beam epitaxy. The crystal quality of SLSs degraded with MgS thickness of more than about 3 monolayers. Photoluminescence due to the transition between quantized levels was observed. Photoluminescence peak energies higher than 3.0 eV at 77 K were observed, which are comparable to that of ZnMgSSe quaternary material. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114820

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We have investigated photoinduced infrared absorption inp‐doped Si/SiGe quantum wells. The absorption spectra exhibit two distinct features: free‐carrier absorption and intersubband absorption in the valence band. The photoinduced absorption in bothpandspolarizations is found to depend on the carrier density and strongly differs from the original absorption of the doped quantum wells. Photoinduced intersubband absorption is attributed to carriers away from the Brillouin zone center. We show that photoinduced intersubband absorption spectroscopy can provide useful information on valence band mixing effects in Si/SiGe quantum wells. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114821

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

High (2 eV) and low kinetic energy supersonic jets of disilane as well as ultrahigh vacuum chemical vapor deposition have been employed to grow epitaxial silicon thin films on Si(100) wafers at temperatures ranging from 500 to 650 °C. The growth properties and film uniformity are compared in order to characterize the high energy technique. High translational energy disilane supersonic jets increase the efficiency of deposition by increasing the disilane reaction probability. The growth profiles from the high energy jet are sharply peaked due to a focusing of the precursor along the jet centerline. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114822

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The technique of ion‐induced quantum well intermixing using broad area, high energy (1 MeV P+) ion implantation has been used to tune the emission wavelength of an InGaAs/InGaAsP/InP multiple quantum well (MQW) laser operating at 1.5 &mgr;m. The optical quality of the band‐gap shifted material is assessed using low‐temperature photoluminescence (PL). The band‐gap tuned lasers are characterized in terms of threshold current density and external quantum efficiency and exhibit blue shifts in the lasing spectra of up to 63 nm. This approach offers the prospect of a powerful and relatively simple fabrication technique for integrating active as well as passive optoelectronic devices. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114823

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A Si single‐electron transistor (SET) with satellite Si islands has been fabricated by pattern‐dependent oxidation of cross‐shaped Si wires on a separation by implanted oxygen (SIMOX) substrate. The oscillatory conductance‐versus‐gate voltage characteristics of the SET show hysteresis as a result of abrupt jumps in the conductance at high temperatures around 30 K. This phenomenon is attributed to the memory effect of a single electron that tunnels between the SET Si island and the satellite Si islands. Time‐resolved measurements have clarified that the conductance jump is a Poisson process, which is clear evidence of the single‐electron tunneling between the Si islands. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114824

出版商:AIP    

年代:1995

数据来源: AIP