摘要:

Doped polycrystalline silicon films have often been used as a diffusion source in the formation of shallow junctions. Conventional furnace annealing of these films with high electrical activation usually results in junctions too deep for submicron devices. In this letter, we report on the results of rapid thermal annealing in the temperature range from 1000 to 1150 °C of arsenic ion‐implanted polycrystalline silicon, characterized by secondary ion mass spectroscopy, Rutherford backscattering and channeling, transmission electron microscopy, and four‐point probe measurements. We demonstrate that with rapid thermal annealing at 1150 °C for 5 s, we can achieve simultaneously a sheet resistance of 20 &OHgr;/&laplac; in the polycrystalline silicon and a diffusion profile of 50 nm into the single‐crystal silicon substrate.

ISSN:0003-6951    

DOI:10.1063/1.97643

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Surface recombination was measured for photowashed and unwashed GaAs using picosecond transient photoreflectance methods. The results for the washed surfaces clearly demonstrate slow surface recombination that is accurately described by an ambipolar diffusion model. The fast decay observed for unwashed samples implies rapid surface recombination involving a more complex mechanism.

ISSN:0003-6951    

DOI:10.1063/1.97644

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The structure of silicon‐on‐insulator formed by oxygen implantation at 150 keV with a dose of 1.6×1018cm−2is studied by high resolution transmission electron microscopy. Polyhedral oxygen precipitates are observed both in the top Si layer and in the substrate after 1150 °C annealing. The oxygen precipitates in the top Si layer coarsen at 1250 °C, but no precipitate can be found in the substrate at this temperature. A layer of polycrystalline silicon (polysilicon) exists near the top Si/buried oxide interface. Silicon crystals in the polysilicon layer also coarsen when the annealing temperature is changed from 1150 to 1250 °C. At 1150 °C, the buried oxide/substrate interface has many Si lamellas roughly parallel to the {100} wafer surface. The lamellar structure is broken up after 1250 °C annealing and is replaced by islandlike crystals which are strongly faceted on {100} planes. Defects are present in Si microcrystallites in both the polysilicon layer and the islandlike particles.

ISSN:0003-6951    

DOI:10.1063/1.97645

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Exact solution in analytical form to the dopant diffusion equation for an arbitrary initial implanted profile is obtained with a judicious choice of variables. The diffusivity can be an arbitrary function of the dopant concentration and the temperature of a sample, provided only that their gradients at the front surface of an ion‐implanted semi‐infinite semiconductor wafer are zero. As an example, we derive a closed‐form expression for the annealed concentration profile for the special case in which the diffusivity is a product of a certain power of the concentration and an arbitrary function of the temperature, the initial dopant concentration profile is a truncated Gaussian, and the temperature dependent part of the diffusivity is initially a Gaussian. The present calculation is a generalization of the data fitting analysis of ion‐implanted dopant profile evolution during annealing by R. Ghez, A. S. Oehrlein, T. O. Sedgwick, F. F. Morehead, and Y. H. Lee [Appl. Phys. Lett.45, 881 (1984)].

ISSN:0003-6951    

DOI:10.1063/1.97646

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The deposition of CdS onto single‐crystalp‐CuInSe2(at a substrate temperature of 200 °C) results in a CuInSe2homojunction rather than the expected heterojunction. Junction depths, varying from 1 to 9 &mgr;m, correlated well with the free‐carrier concentration of the sample crystals. The junction depths were measured by electron‐beam‐induced current line scans of cleaved junctions and were corroborated by quantum efficiency measurements. All the materials deposited to date (CdS, Cd, Au, and Mo) have resulted in type conversion of the CuInSe2. The experimental evidence for this type conversion is presented and possible defect chemical origins identified.

ISSN:0003-6951    

DOI:10.1063/1.97647

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We report photocollection efficiency measurements ofp+inGaAs/AlAs/GaAs diodes fabricated on films grown by molecular beam epitaxy. Both the zero‐bias and bias‐dependent photocollection characteristics can be explained by assuming that the band discontinuity between AlAs and GaAs is mostly accommodated in the valence band.

ISSN:0003-6951    

DOI:10.1063/1.97648

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The recently discovered order‐disorder transformations in pseudobinary semiconductor alloysAxB1−xCare shown to belong to a broader class of such transformations inAnB4−nC4semiconducting compounds (e.g., chalcopyrites, forn=2). Strain energy, set up by the atomic size mismatch between theA–CandB–Cbonds, is shown to control the nature of the state of order in chalcopyrites and pseudobinary alloys alike. These considerations lead to a classification of all bulk tetrahedral semiconductors into four classes of order‐disorder characteristics.

ISSN:0003-6951    

DOI:10.1063/1.97649

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Joule displacement microscopy, where the periodic expansion caused by Joule heating in a thin‐film track carrying ac current is mapped using a focused probe, has recently been described. In this letter, we demonstrate the application of this technique to the study of current distribution within a bipolar inverting gate.

ISSN:0003-6951    

DOI:10.1063/1.97650

出版商:AIP    

年代:1987

数据来源: AIP