Abstract: A process improvement for enabling the development of low cost transistor devices, particularly MOS FETs, in annealed polysilicon formed on an insulator; the improvement resulting from the use of silicon ribbons as substrates.

Abstract: A silicon dendrite is grown as a ribbon forming two silicon crystal layers which are separated by an interface layer which contains a large number of defects. Significant increase of minority carrier lifetime with homogeneous distribution at the outer surfaces of the two silicon crystal layers are achieved by processing the web in an atmosphere of a selected gas, e.g. oxygen, nitrogen or an inert gas, for about 30 minutes to several hours at a temperature preferably on the order of 900.degree. C.-1200.degree. C.

Abstract: A method and apparatus for drawing a monocrystalline ribbon or web from a melt comprising utilizing a shaping die including at least two elements spaced one from the other each having a portion thereof located below the level of the melt and another portion located above the level of the melt a distance sufficient to form a raised meniscus of melt about the corresponding element.

Abstract: A semiconductor wafer into which devices such as an integrated circuit is to be formed is gettered by regions in the wafer activated by a laser beam. The laser beam is directed onto the surface of the wafer opposite to that where the devices are to be formed. The power input to the laser is controlled such that the surface temperature of the region of the semiconductor wafer where the laser beam is applied first reaches the melting point of the material, such as silicon, and the melting commences. Then the temperature in the melt rises above the melting temperature, but stays below the boiling temperature of the material of the wafer. A superheated melt is formed. The result is that the solid-liquid interface moves deep into the material. The position of the melt is directly under the laser beam. The solidified material is positioned behind the beam as the beam scans the wafer. A depression is formed under the beam while the material rises behind the laser beam.

Abstract: A method for growing silicon crystalline material by the directional solidification method without cracking the growth container. The container material must have an average thermal expansion coefficient of between about 3.0 to 4.3.times.10.sup.-6 .degree.C..sup.-1 between about 20.degree. and 650.degree. C. The molten silicon is provided in the container and solidified sequentially from the enclosed regions to the open region of the container to form the crack-free silicon crystalline material.

Abstract: Methods of making semiconductor devices using the technique of impact sound stressing are disclosed. Impact sound stressing (ISS) is a mechanical acoustical technique to damage, in a known and controlled manner, semiconductor wafers. Wafers are subjected to ISS on the backsides before semiconductor processing steps. The application of ISS before the first high temperature application will control the generation and subsequent direction of flow (gradient) of vacancies (interstitials) generated through all device high temperature processing steps including ion implantation. ISS redirects the flow of vacancies/interstitials into the backside away from the device area of the wafer. Thus, the device area is swept clean in a gettering action of vacancy/interstitials and their complexes which are detrimental to device performance. The technique of impact sound stressing finds application in improving the performance of all semiconductor devices, specifically dynamic memories, bipolars, solar cells and power devices.

Abstract: Apparatus for acoustical stressing of semiconductor wafers is disclosed, utilizing a number of small tungsten balls which are bounced on the surface of the wafer to be stressed. The movement of the tungsten balls is effectuated by clamping a wafer at one end of a conduit, the other end being attached to a high intensity loudspeaker. The loudspeaker is driven at resonant frequency of the clamped wafer and accordingly the tungsten balls bounce on the surface. This impact creates micro-cracks on the surface of the wafer and number and depth of these cracks can be controlled by power input and the number of tungsten balls utilized. Controlled stressing can thereby be accomplished both in terms of density of micro-cracks and location on the wafer.Impact sound stressing finds utilization in the study of semi-conductor surfaces to determine effects of dislocations and micro-splits and in the evaluation of wafer polishing techniques.