摘要:
The present invention provides a methods and system for producing semiconductor grade single crystals that are substantially free of undesirable agglomerated defects. A vacancy/interstial (V/I) boundary simulator analyzes various melt-solid interface shapes to predict a corresponding V/I transition curve for each of the various melt-solid interface shapes. A target melt-solid interface shape corresponding to a substantially flat V/I curve is identified for each of a plurality of axial positions along the length of the crystal. Target operating parameters to achieve each of the identified melt-solid interface shapes are stored in a melt-solid interfaced shape profile. A control system is responsive to the stored profile to generate one or more control signals to control one or more output devices such that the melt-solid interfaced shape substantially follows the target shapes as defined by the profile during crystal growth.
摘要:
A crystal puller and method for growing monocrystalline silicon ingots includes first and second electrical resistance heaters in the crystal puller in longitudinal, closely spaced relationship with each other to radiate heat toward the ingot as the ingot is pulled upward within the housing. In one embodiment, the first heater is powered when the ingot is pulled upward to a first axial position above the surface of the molten silicon and the second heater is powered when the ingot is pulled upward to a second axial position above the first axial position. In another embodiment the first and second heaters are powered until the ingot is separated from the molten silicon and then the heating power output of the first and second heaters is reduced to substantially increase the cooling rate at which the ingot is cooled. An adapter mounting the heaters may also be provided for adapting existing crystal pullers to incorporate the heaters.
摘要:
A crystal puller for growing monocrystalline silicon ingots includes first and second electrical resistance heaters in the crystal puller in longitudinal, closely spaced relationship with each other to radiate heat toward the ingot as the ingot is pulled upward within the housing. An adapter mounting the heaters may also be provided for adapting existing crystal pullers to incorporate the heaters.
摘要:
Provided are organic aerogel foams and their method of manufacture from polyfunctional vinyl monomers, such as trimethylolpropane trimethacrylate and/or ethoxylated trimethyol trimethacrylate, which foams are ideally suited for filtering media, and especially for microorganism filtration for capture of bacteria, viruses, yeast and other microparticles.
摘要:
An angle of repose valve for controlling the flow of granules and a method of repairing a leak in an angle of repose valve are disclosed herein. The angle of repose valve has a housing with an interior cavity, an inlet, and an outlet. A gas is used to convey granules through the valve and the housing has a thickness such that the gas can have a pressure of at least 70 psi. A saddle is disposed in the interior cavity of the housing and is coupled to a rotatable shaft that passes through an opening in the housing. A chevron seal is disposed between the shaft and a sealing member. A compression member is threadably engaged with the sealing member and is operable to exert force on the chevron seal to expand the chevron seal against the shaft and/or the housing to prevent and/or repair leaks of gas therethrough.
摘要:
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.