A method is proposed to prepare ultrathin silicon oxynitride films for gate dielectrics used in deep submicron metal–oxide–semiconductor field effect transistor device structures, namely plasma immersion N implantation into SiO2 films. Plasma immersion implantation pulse voltages in the range 200–1000 V, and fluences from 1016 to 1017 N cm−2 were implanted into thermally grown SiO2 films, with thicknesses between 3 and 6 nm. The areal densities of N and O in the resulting oxynitride films were determined by nuclear reaction analysis, before and after annealing in high-vacuum. N, O, and Si profiles in the films were determined with subnanometric depth resolution by medium energy ion scattering. The results indicate that plasma immersion ion implantation allows for shallow and controlled deposition of significant amounts of nitrogen (up to 3.8 nm of equivalent Si3N4 thickness). Implantation is accompanied by moderate damage at the oxynitride/Si interface which can be recovered by thermal annealing.

General trends in integrated circuit technology toward smaller device dimensions, lower thermal budgets, and simplified processing steps present severe physical and engineering challenges to ion implantation. These challenges, together with the need for physically based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in Si. In this article, we review the current status and future trends in ion implantation of Si at low and high energies with particular emphasis on areas where recent advances have been made and where further understanding is needed. Particularly interesting are the emerging approaches to defect and dopant distribution modeling, transient enhanced diffusion, high energy implantation and defect accumulation, and metal impurity gettering. Developments in the use of ion beams for analysis indicate much progress has been made in one-dimensional analysis, but that severe challenges for two-dimensional characterization remain. The breadth of ion beams in the semiconductor industry is illustrated by the successful use of focused beams for machining and repair, and the development of ion-based lithographic systems. This suite of ion beam processing, modeling, and analysis techniques will be explored both from the perspective of the emerging science issues and from the technological challenges.

We report chemical vapor deposition growth of SiGeC layers on 〈100〉 Si substrates. At the growth temperature of 550 °C, the C concentration as high as 2% can be incorporated into SiGe (Ge content ∼ 25%) to form single crystalline random alloys by using low flow of methylsilane (0.25 sccm) as a C precursor added in a dichlorosilane and germane mixture. For intermediate methylsilane flow (0.5 sccm – 1.5 sccm), the Fourier transform infrared spectroscopy (FTIR) absorption spectra indicate the growth of amorphous layers. For the layers with high flow of methylsilane (12 sccm), there are silicon-carbide-like peaks in the FTIR spectra, indicating silicon carbide precipitation. The films were also characterized by x-ray diffraction, high resolution transmission electron microscopy, secondary ion mass spectroscopy, and Rutherford backscattering spectroscopy to confirm crystallinity and constituent fractions. The defect-free band-edge photoluminescence at both 30 K and 77 K was observed in Si/SiGeC/Si quantum wells, even at power densities as low as 0.5 W/ cm2 and 1 W/cm2, respectively. Deep photoluminescence around 0.8 eV and luminescence due to D3 dislocations at 0.94 eV were not observed under any excitation conditions.

Silicon is the driving force behind the information superhighway, multimedia and all the other much-hyped trends that have suddenly been noticed by the media in the past two years. This information revolution has been made possible by the phenomenal advances in the manufacture of silicon-based integrated circuits. The cost of storing or processing a single bit of information has fallen by factors of a million over the last couple of decades. Indeed, consumers can now put the equivalent of a 1983 supercomputer on their kitchen table.

Surface energy anisotropy, as opposed to surface energy, is shown to influence changes of growth mode in Ge/Si by ''surfactant'' impurities. By annealing thin Ge/Si films, we find the equilibrium island shape, and hence the surface energy anisotropy; radical changes in shape are seen for impurity-terminated surfaces: Ge:Sb enhances (100) facets compared to clean Ge and Ge:In favors {311}. Thus Sb impurities favor large flat islands which would lead to earlier island coalescence and can aid planar (100) growth, while In (though otherwise a good ''surfactant'') leaves the film faceted. Island suppression by a ''morphactant'' thus depends on enhanced faceting onto (100), as well as reduced diffusion.

Thick amorphous Si layers have been prepared by MeV self-ion-implantation and the thermodynamic and structural properties examined by calorimetry, Raman-spectroscopy, and x-ray-diffraction techniques. Defects have been introduced into well-annealed amorphous and single-crystal Si by He, C, Si, and Ge bombardment. The defect structures are examined by these techniques and by transmission electron microscopy. The structure of amorphous Si in intermediate states of relaxation or annealing have been determined. It is shown that amorphous Si formed by either implantation or deposition contains a large population of point defects and point-defect clusters. Amorphous Si formed by laser quenching cannot be distinguished from well-annealed amorphous Si. Structural relaxation, also known as short-range ordering, can be understood as annihilation of a large fraction of these defects. Both structural relaxation in amorphous Si and defect annihilation in crystalline Si obey bimolecular reaction kinetics. The defect-formation and -annihilation processes are similar in amorphous and crystalline Si. Defect saturation occurs in amorphous Si at estimated defect concentrations of about 1 at. %. These formation and annihilation properties are intrinsic to pure amorphous Si. For hydrogenated amorphous Si, it is pointed out that the metastable-defect-creation and -annealing processes are essentially different from the annihilation processes in pure amorphous Si.

We show that the islands formed in Stranski-Krastanow (SK) growth of Ge on Si(100) are initially dislocation free. Island formation in true SK growth should be driven by strain relaxation in large, dislocated islands. Coherent SK growth is explained in terms of elastic deformation around the islands, which partially accommodates mismatch. The limiting critical thickness, ${\mathit{h}}_{\mathit{c}}$, of coherent SK islands is shown to be higher than that for 2D growth. We demonstrate growth of dislocation-free Ge islands on Si to a thickness of \ensuremath{\approxeq}500 \AA{}, 50\ifmmode\times\else\texttimes\fi{}higher than ${\mathit{h}}_{\mathit{c}}$ for 2D Ge/Si epitaxy.