Abstract: A practical photovoltaic module is disclosed which is protected from reverse bias damage and which displays minimal power loss resulting from temporary inoperativeness of one or more individual photovoltaic cells included in the module. The module includes a plurality of series connected photovoltaic cells. Protection from inoperativeness of one or more of these cells is provided with only minimal power loss by providing a reversely poled diode across each of the series connected cells.

Abstract: Implanting, with low energy (e.g. 75 Kev and below), a dose of boron difluoride (BF.sub.2) into an area on a silicon substrate which is post-damaged or pre-damaged by a silicon implant so that annealing, or activation, can be accomplished at temperatures in the range of 550.degree. C. to 900.degree. C.

Abstract: Apparatus is provided for semiconductor ribbon-to-ribbon conversion in a rigid edge mode. A combination carrier and mask is provided by which the ribbon is secured during the conversion process. The carrier holds the ribbon and simultaneously masks the edges of the ribbon from the heating effects of an impinging energy beam. The energy beam, such as a laser or electron beam, impinges on the ribbon and creates a molten zone which extends through the thickness of the ribbon. During the growth process, the molten zone is caused to move along the length of the ribbon. The mask prevents melting of the extreme edge portions of the ribbon and thus allows a rapid growth rate and a stable molten zone without sophisticated electronic equipment to gate the energy beam at the ribbon edges.

Abstract: A structure is provided which affords radiation protection to semiconductor devices and which specifically prevents soft failures in semiconductor memories caused by alpha particle radiation. The protection is provided by a metallic radiation shield formed on but insulated from the semiconductor memory array. The radiation shield is formed on the semiconductor devices while they are still in wafer form but after the normal device fabrication has been completed.

Abstract: A method is provided for converting polycrystalline ribbon to macrocrystalline ribbon in which a molten zone is formed in and moved along the polycrystalline ribbon. Macrocrystalline material in ribbon shape is formed as the molten region passes and the molten material resolidifies. The molten zone is formed in the polycrystalline ribbon by impinging energy beams from two energy sources on the two major surfaces of the ribbon. The combined energy from the first and second energy sources is sufficient to melt the ribbon material and to form a molten zone extending through the thickness of the ribbon. The molten zone has an intersection with each of the major surfaces of the ribbon. The two energy sources are adjusted independently to control the area of the intersection of the molten zone with each surface so that the areas are non-identical.

Abstract: A process is disclosed for the purification of trichlorosilane and other silicon source materials. Trace impurities of boron and phosphorous are removed from trichlorosilane or dichlorosilane by reacting small amounts of oxygen with the trichlorosilane or dichlorosilane at a temperature between about 60.degree. C. and 300.degree. C. The oxygen reacts with the Si--H bond in HSiCl.sub.3 or H.sub.2 SiCl.sub.2 to form a "SiOH" species which in turn complexes impurities such as BCl.sub.3 or PCl.sub.3 present in the chlorosilane. Purification of the chlorosilane is then easily accomplished during a subsequent distillation step which separates the purified chlorosilane from the less volatile complexed boron or phosphorous compounds.

Abstract: A self-actuated charge container is open at one end except for deformable support members which are positioned to support the charge material. The support members are formed of a material which has sufficient rigidity at room temperature to support the charge material but which when heated above its annealing temperature loses its rigidity and can no longer support the charge material which therefore falls into the existing melt. Upon cooling, the support members regain their rigidity and can be reformed for reuse.

Abstract: A method is provided for predepositing dopant material on semiconductor substrates. The semiconductor substrates are positioned within a high pressure plasma reactor apparatus. A high pressure rf plasma is generated in the apparatus at a pressure of about one atmosphere or greater. Dopant materials such as B.sub.2 H.sub.6, PH.sub.3, or AsH.sub.3 are introduced to the plasma and form ionized species of the dopant. The plasma and the ionized species are directed to the surface of the semiconductor substrates whereon a uniform layer of the dopant is deposited.

Abstract: A process is disclosed for fabricating a MOS ROM which allows programming of the ROM late in the process sequence. A conventional silicon gate process is used to fabricate the devices up through the step of patterning the polycrystalline silicon gate electrode. Selected devices in the array are then programmed to an off-state by fabricatng those devices with either the source or drain region offset from the gate electrode. This is accomplished by a programming mask which, together with the gate electrode, provides selective location of the source or drain regions. Devices having an offset source or drain are off-state devices, while those having a normal source and drain function conventionally and conduct when a read voltage is applied.

Abstract: A process is disclosed for the purification of trichlorosilane and other silicon source materials. Trace impurities of boron and phosphorous are removed from trichlorosilane by reacting small amounts of oxygen with the trichlorosilane at a temperature between about 170.degree. and 300.degree. C. The oxygen reacts with the Si--H bond in HSiCl.sub.3 to form a "SiOH" species which in turn complexes impurities such as BCl.sub.3 or PCl.sub.3 present in the trichlorosilane. Purification of the trichlorosilane is then easily accomplished during a subsequent distillation step which separates the purified trichlorosilane from the less volatile complexed boron or phosphorous compounds.

Abstract: A process is provided for forming a self-supporting semiconductor film or ribbon. A TESS substrate is prepared from a substrate of refractory material having an expansion coefficient different from the expansion coefficient of the semiconductor material. A colloidal suspension of graphite is applied to the substrate to form a thin layer of loosely adherent graphite particles. Over this layer of graphite is deposited a layer of the semiconductor material, the deposition occurring at an elevated temperature. Upon cooling from the deposition temperature, the differential thermal expansion coefficience causes the shearing at the graphite layer and therefore provides for the easy removal of the semiconductor layer from the substrate.

Abstract: An apparatus and method for controlling a plasma etching reaction. The plasma reaction is controlled by monitoring the output voltage of an optical detector which is responsive to emissions emanating from the reaction. As the output of the detector changes indicating that the first portion of the etching process has been completed, the average power density supplied to the reaction is reduced by switching the applied power from a continuous wave to a pulsed mode. The reaction is allowed to continue to completion in the reduced power mode.

Abstract: A solder composition for bonding a semiconductor die to a plated or unplated metal package member. In one embodiment the solder composition comprises, in weight percent, 5-8 copper, 20-40 silver, and the balance tin. Such a composition is particularly efficacious for bonding to copper and copper alloy package members. A further embodiment particularly efficacious for bonding to nickel and nickel alloy members further comprises the addition of 0.5-3.0 weight percent selenium.

Abstract: A solution is disclosed for the one-step etching of a three layer titanium-nickel-copper metallization. The etch solution comprises about 1.8 to 2.0 moles/liter hydrofluoric acid, about 2.5 to 4.0 moles/liter acetic acid, about 8.7 to 9.0 moles/liter nitric acid, and balance water. Use of the solution permits the patterned etching of sequential layers of titanium, nickel, and copper without excessive attack of underlying silicon dioxide layers.

Abstract: A method for the controlled melting of an end of a polycrystalline semiconductor body. The polycrystalline body is divided into two or more segments and the segments are positioned in a spaced apart relationship so as to be electrically isolated from each other by narrow gaps. One end of the segments is heated by an external heating means such as by induction heating to cause a portion of the end of the segments to melt. Some of the molten material so formed then flows into the gap separating the segments and electrically shorts together the segments. The opposite ends of the segments are connected to an electrical power supply and a heating current is passed through the segments and through the molten material bridging the gaps. Separately adjusting the heating effects of the external heating means and the heating current makes possible the controlled heating and controlled melting of the end portions of the segments.

Abstract: Polycrystalline silicon is produced by a high pressure plasma process. A silicon halide or halosilane is reacted with hydrogen in the presence of a high pressure plasma to deposit silicon on a heated substrate. The effluent from this reaction is collected, the silicon-bearing compounds separated out, and re-introduced to the deposition reaction. The initial silicon bearing compound can be inexpensive silicon tetrachloride. Maximum utilization of all silicon bearing reaction products maximizes polycrystalline silicon production efficiency.

Abstract: A self-aligned MOS transistor having improved operating characteristics and higher packing density and a method for fabricating the device. Resistance of the gate electrode is reduced substantially by forming the electrode of a metal silicide. Resistance of the source and drain regions is likewise reduced substantially by forming a metal silicide in the doped junction region which allows those regions to be smaller and to require less area. The silicided source and drain regions are self-aligned with and closely spaced to the silicided gate electrode. This is provided by a process which utilizes and makes possible an undercut etching of a polycrystalline silicon gate electrode.

Abstract: A monolithic silicon pressure sensor employing a four-terminal resistive element is formed in a thin monocrystalline silicon diaphragm. The resistive element is a diffused resistor having current contacts at the ends and two voltage contacts located midway between the current contacts and on opposite sides of a current axis defined between the two current contacts. The thin silicon diaphraghm has a square shape and is oriented in a (100) silicon surface with its sides parallel to a [110] crystal orientation. The resistor is oriented with its current axis parallel to a [100] crystalline direction and at 45 degrees with respect to the edge of the diaphragm to maximize sensitivity of the resistor to shear stresses generated by flexure of the diaphragm resulting from pressure differentials across the diaphragm.

Abstract: A method is disclosed for the plasma hydrogenation of silicon tetrachloride. A high pressure plasma is utilized to effect a reaction of hydrogen and silicon tetrachloride to form trichlorosilane and other hydrogenated silicon chlorides.

Abstract: A method for achieving active devices with closely matched characteristics for use in high performance monolithic integrated circuits. The method comprises providing active devices with appropriately segmented junction regions connected in parallel by their metallic links and severing one or more of the links in order to achieve matching of both the static and dynamic characteristics of two or more active devices.