Amorphous layers, approximately 4000 A thick, were formed on single‐crystal Si samples by implantation of 28Si ions at LN2 substrate temperature. Channeling‐effect measurements with MeV 4He ions were used to measure the thickness of the amorphous layers and to measure the subsequent epitaxial regrowth on the underlying crystalline substrates. For annealing temperatures between 450 and 575 °C, the growth rate showed a strong dependence on the substrate orientation with 〈100〉‐oriented samples exhibiting about a 25 times higher growth rate than 〈111〉‐oriented samples. Measurements of the growth rate on a series of samples cut in 5° angular increments show that there is a monotonic decrease from the 〈100〉 to the 〈111〉 orientation. A simple model is proposed to explain the observed orientation dependence.

Substrate‐orientation dependence of the epitaxial regrowth rate from Si‐implanted amorphous Si

Buried SiO2, layers were formed by oxygen-ion (14O+) implantation into silicon. The impurity distribution of the oxygen-implanted silicon substrate was analysed by auger spectroscopy. The epitaxially-grown silicon layer on this substrate showed a good monocrystalline structure, and a 19-stage c.m.o.s. ring oscillator exhibited high performance in operation.

C.M.O.S. devices fabricated on buried SiO2 layers formed by oxygen implantation into silicon

We derive a stochastic nonlinear continuum equation to describe the morphological evolution of amorphous surfaces eroded by ion bombardment. Starting from Sigmunds theory of sputter erosion, we calculate the coefficients appearing in the continuum equation in terms of the physical parameters characterizing the sputtering process. We analyze the morphological features predicted by the continuum theory, comparing them with the experimentally reported morphologies. We show that for short time scales, where the effect of nonlinear terms is negligible, the continuum theory predicts ripple formation. We demonstrate that in addition to relaxation by thermal surface diffusion, the sputtering process can also contribute to the smoothing mechanisms shaping the surface morphology. We explicitly calculate an effective surface diffusion constant characterizing this smoothing effect and show that it is responsible for the low temperature ripple formation observed in various experiments. At long time scales the nonlinear terms dominate the evolution of the surface morphology. The nonlinear terms lead to the stabilization of the ripple wavelength and we show that, depending on the experimental parameters, such as angle of incidence and ion energy, different morphologies can be observed: asymptotically, sputter eroded surfaces could undergo kinetic roughening, or can display novel ordered structures with rotated ripples. Finally, we discuss in detail the existing experimental support for the proposed theory and uncover novel features of the surface morphology and evolution, that could be directly tested experimentally. � 2002 Published by Elsevier Science B.V.

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Morphology of ion-sputtered surfaces

An object is to provide a method for manufacturing a semiconductor device, in which the number of photolithography steps can be reduced, the manufacturing process can be simplified, and manufacturing can be performed with high yield at low cost A method for manufacturing a semiconductor device includes the following steps: forming a semiconductor film; irradiating a laser beam by passing the laser beam through a photomask including a shield for shielding the laser beam; subliming a region which has been irradiated with the laser beam through a region in which the shield is not formed in the photomask in the semiconductor film; forming an island-shaped semiconductor film in such a way that a region which is not irradiated with the laser beam is not sublimed because it is a region in which the shield is formed in the photomask; forming a first electrode which is one of a source electrode and a drain electrode and a second electrode which is the other one of the source electrode and the drain electrode; forming a gate insulating film; and forming a gate electrode over the gate insulating film

Method for Manufacturing Semiconductor Device

The formation of supersaturated substitutional alloys by ion implantation and rapid liquid‐phase‐epitaxial regrowth induced by pulsed laser annealing has been studied using Rutherford backscattering, ion channeling analysis. Group‐III (Ga, In) and group‐V (As, Sb, Bi) dopants have been implanted into single‐crystal silicon at doses ranging from 1×1015 to 1×1017/cm2. The samples were annealed with a Q‐switched ruby laser (energy density ∼1.5 J/cm2, pulse duration ∼15×10−9 sec). Ion channeling analysis shows that laser annealing incorporates these dopants into substitutional lattice sites at concentrations far in excess of the equilibrium solid solubility. Channeling measurements indicate the silicon crystal is essentially defect free after laser annealing. Also values for the maximum dopant concentration (Cmaxs) that can be incorporated into substitutional lattice sites are determined for our annealing conditions. Dopant profiles determined by Rutherford backscattering are compared to model calculations wh...

R. S. Nelson

Papers

Ion implantation