Abstract: A method of processing a semiconductor wafer sliced from a single-crystal ingot includes lapping front and back surfaces of the wafer to reduce the thickness of the wafer and to improve the flatness of the wafer. The front surface is subjected to fine grinding to reduce the damage on the front surface while leaving damage on the back surface intact. The front and back surfaces are simultaneously polished to improve the flatness of the wafer and to reduce wafer damage on the front and back surfaces. The wafer damage remaining on the back surface is greater than the wafer damage on the front surface. The wafer damage remaining on the back surface facilitates gettering.

Abstract: A collector and method for collecting samples of liquid from at least one source of liquid for automated analysis of the samples. The collector has at least one receptacle for receiving liquid from the source of liquid and holding a quantity of the liquid for obtaining a sample. Each receptacle has an inlet for delivery of liquid from the respective source of liquid and an open top sized to admit the sample collection device into the receptacle. The collector also has a spillway in fluid communication with the open top of the receptacle for receiving excess liquid spilling over the open top of the receptacle. The collector is constructed so that liquid continuously flows through the collector. A drain of the collector receives liquid from the spillway for draining the liquid from the collector.

Abstract: A control method for use with a Czochralski crystal puller. The method includes pulling the growing crystal from the melt at a first target pull rate to grow a taper portion of the crystal and measuring the crystal diameter of the taper. The method also includes estimating a slope of the diameter as a function of a change in crystal diameter relative to time and the first target pull rate. The method further includes predicting a crystal diameter Di at which to initiate body growth from the taper as a function of the estimated slope. By increasing the pull rate to a second target pull rate when the measured crystal diameter reaches the predicted crystal diameter Di, the method controls growth of the crystal for transitioning from taper growth to body growth. The method also determines the second target pull rate as a function of the estimated slope when using a predefined diameter Di at which to initiate growth of the crystal body.

Abstract: A cable assembly for supporting a seed chuck in a crystal puller to grow monocrystalline ingots according to the Czochralski method comprises a cable adapted for generally vertical movement within the crystal puller relative to a source of molten material. A chuck support is connected to an end of the cable within the crystal puller and is configured for supporting the seed chuck. The chuck support is constructed of a refractory material having a high creep rupture strength and comprises an elongate shank having an upper end and a lower end and an enlarged end member at the lower end of the shank. A coupling is constructed of a malleable material and is deformable into engagement with the end of the cable and the upper end of the shank to join the chuck support to the cable.

Abstract: A process for heat-treating a single crystal silicon wafer to influence the precipitation behavior of oxygen in the wafer in a subsequent thermal processing step. The wafer has a front surface, a back surface, a central plane between the front and back surfaces, and a sink for crystal lattice vacancies at the front surface. In the process, the wafer is subjected to a heat-treatment to form crystal lattice vacancies, the vacancies being formed in the bulk of the silicon. The wafer is then cooled from the temperature of said heat treatment at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the crystal lattice vacancy sink to produce a wafer having a vacancy concentration profile in which the peak density is at or near the central plane with the concentration generally decreasing in the direction of the front surface of the wafer.

Abstract: A process for reducing the waviness of a semiconductor wafer utilizing plasma assisted chemical etching is disclosed. The process includes measuring the surface profile at discrete points on one surface of the wafer independent from the apposing surface, computing a dwell time versus position map based on the measured surface profiles, and selectively removing material from each surface of the wafer by plasma assisted chemical etching to reduce the waviness of the wafer.

Abstract: A heat shield for a crystal puller including an inner and an outer reflector. The inner and outer reflectors are spaced from each other an have reduced surface area in which they contact each other. Improved heat shielding of a growing crystal ingot reduces defects and permits a greater throughput of ingots produced by the crystal puller.

Abstract: A single crystal silicon wafer which, during the heat treatment cycles of essentially any electronic device manufacturing process, will form an ideal, non-uniform depth distribution of oxygen precipitates. The wafer is characterized in that is has a non-uniform distribution of crystal lattice vacancies, the concentration of vacancies in the bulk layer being greater than the concentration of vacancies in the surface layer and the vacancies having a concentration profile in which the peak density of the vacancies is at or near a central plane with the concentration generally decreasing from the position of peak density in the direction of a front surface of the wafer. In one embodiment, the wafer is further characterized in that it has a first axially symmetric region in which vacancies are the predominant intrinsic point defect and which is substantially free of agglomerated intrinsic point defects, wherein the first axially symmetric region comprises a central axis or has a width of at least about 15 mm.

Abstract: A multi-step polishing process for producing dopant-striation-free semiconductor wafers. The process includes polishing a surface of the wafer using a sodium stabilized colloidal silica slurry, an amine accelerant, and an alkaline etchant, polishing the surface of the wafer using a sodium stabilized colloidal silica slurry and an alkaline etchant which is substantially free of amine accelerants, and polishing the surface of the wafer using an ammonia stabilized colloidal silica slurry and an alkaline etchant which is substantially free of amine accelerants.

Abstract: A process for heat-treating a single crystal silicon wafer to influence the precipitation behavior of oxygen in the wafer in a subsequent thermal processing step is disclosed. The wafer has a front surface, a back surface, and a central plane between the front and back surfaces. In the process, the wafer is subjected to a heat-treatment to form crystal lattice vacancies, the vacancies being formed in the bulk of the silicon. The heat-treated wafer is then oxidized by heating in the presence of an oxygen-containing atmosphere in order to establish a vacancy concentration profile within the wafer. The oxidized wafer is then cooled from the temperature of said oxidizing heat treatment at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a wafer having a vacancy concentration profile in which the peak density is at or near the central plane with the concentration generally decreasing in the direction of the front surface of the wafer.

Abstract: A process for preparing a quartz crucible having a tungsten doped layer on the inside surface, outside surface, or both the inside surface and the outside surface is disclosed. One or more surfaces of the crucible is exposed to a vaporous tungsten source to anneal the tungsten into the crucible surface and create a tungsten doped layer which behaves similarly to a bubble free layer upon use in a crystal pulling process.

Abstract: A method and apparatus for producing silicon single crystals with reduced contamination is disclosed. In one embodiment the structural components constructed of graphite and located in the hot zone of the crystal pulling apparatus have two protective layers. The first protective layer is applied directly to the graphite component. The second protective layer is a silicon layer and is applied on top of the first protective layer and covers the first layer. In a second embodiment, the structural components constructed of graphite and located in the hot zone of the crystal pulling apparatus have a single protective layer. The single protective layer is applied directly to the graphite and consists of a mixture of silicon carbide and silicon.

Abstract: A process for joining together a first polishing pad with a second polishing pad to form a larger pad for a machine that performs chemical-mechanical polishing of silicon wafers. The process includes laying a first polishing pad on a surface and laying a second pad on the surface so that a portion of the second pad overlies a portion of the first pad, creating an overlap region. The first and second pads in the overlap region are cut through to form a first cut edge on the first pad and a second cut edge on the second pad, the first and second cut edges having shapes which are complementary. The first and second cut edges are brought into engagement, and the first pad is joined to the second pad at the first and second cut edges.

Abstract: A process for heat-treating a single crystal silicon wafer to influence the precipitation behavior of oxygen in the wafer in a subsequent thermal processing step. The wafer has a front surface, a back surface, and a central plane between the front and back surfaces. In the process, the wafer is subjected to a heat-treatment to form crystal lattice vacancies, the vacancies being formed in the bulk of the silicon. The wafer is then cooled from the temperature of said heat treatment at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a wafer having a vacancy concentration profile in which the peak density is at or near the central plane with the concentration generally decreasing in the direction of the front surface of the wafer.

Abstract: A process for extracting inorganic ionic contaminants from a front surface of a silicon wafer for chemical analysis. The wafer is placed in a container upon a support which holds the wafer in a generally level orientation and isolates the wafer to inhibit air circulation over the front surface. Air circulation can introduce contaminants to the extraction fluid, causing a false measurement of contaminants on the wafer. A layer of extraction fluid is deposited upon only the front surface of the wafer and held for a period of time so that contaminants on the front surface are extracted into the layer of fluid. A portion of the layer of fluid is collected by a sampling device for subsequent analysis.

Abstract: A method and system for determining melt level and reflector position in a Czochralski single crystal growing apparatus. The crystal growing apparatus has a heated crucible containing a silicon melt from which the crystal is pulled. The crystal growing apparatus also has a reflector positioned within the crucible with a central opening through which the crystal is pulled. A camera generates images of a portion of the reflector and a portion of a reflection of the reflector visible on the top surface of the melt. An image processor processes the images as a function of their pixel values to detect an edge of the reflector and an edge of the reflection in the images. A control circuit determines a distance from the camera to the reflector and a distance from the camera to the reflection based on the relative positions of the detected edges in the images.

Abstract: The present invention is directed to a process for evaluating a silicon wafer having a n-type or a p-type epitaxial layer on the surface thereof. In a first embodiment, an oxide layer is formed on the surface of a n-type epitaxial wafer by exposing the wafer to ultraviolet light while in the presence of oxygen. The wafer is then subjected to a capacitance-voltage measurement to evaluate the characteristics of the epitaxial layer. In a second embodiment, an oxide layer is dissolved from the surface of a p-type epitaxial wafer by passing a gaseous mixture comprising an inert carrier gas and hydrofluoric acid vapors over the surface of the wafer. The wafer is then subjected to a capacitance-voltage measurement to evaluate the characteristics of the epitaxial layer.

Abstract: An apparatus for extracting inorganic ionic contaminants from a front surface of a silicon wafer for chemical analysis. The apparatus includes a container adapted to receive the wafer and inhibit air circulation over the front surface of the wafer. The container has a support for holding the wafer in a generally level orientation with the front surface of the wafer facing upwardly, an inlet orifice for introducing a layer of extraction fluid to the front surface of the wafer, and a sampling device for taking a sample from the layer of extraction fluid on the front surface of the wafer. The layer of extraction fluid is deposited upon only the front surface of the wafer and held for a period of time so that contaminants on the front surface are extracted into the layer of fluid. The container inhibits air circulation over the front surface of the wafer to preclude introducing contaminants to the extraction fluid that cause a false measurement of contaminants on the wafer.

Abstract: A method of conditioning a polishing pad for use with a polishing machine. The method includes installing the polishing pad to be conditioned on the polishing machine's platen and applying a conditioning load force to the pad. In addition, the method includes supplying a slurry to the pad at a conditioning flow rate. The conditioning load force is greater than a polishing load force applied during a conventional wafer polishing cycle to compress the pad and the conditioning flow rate is greater than a polishing flow rate at which the slurry is supplied during the wafer polishing cycle to load the pad's pores with abrasive material. The method also includes the step of operating the polishing machine for a conditioning cycle while applying the conditioning load force and supplying the slurry at the conditioning flow rate. In this manner, the polishing pad is conditioned for use with the polishing machine for subsequently polishing the semiconductor wafers with the conditioned pad.

Abstract: A susceptor for supporting wafers in a reaction chamber of a barrel reactor during a chemical vapor deposition process. The susceptor includes a body sized and shaped for receipt within the reaction chamber of the barrel reactor. The body includes a generally laterally facing, sloped face having a plurality of circular recesses therein for receiving wafers to support the wafers with one surface directed generally laterally outward for exposure to reactant gas inside the reaction chamber of the barrel reactor during the chemical vapor deposition process. Each of the plurality of recesses has a substantially planar bottom and opposing arcuate wall portions on opposite sides of the planar bottom. Each wall portion intersects and merges with a corresponding wall portion of at least one adjoining recess of the plurality of recesses at an intersection.