Abstract: In Czochralski crystal growing operations, particularly those involving growth of silicon crystals, projecting formations of silicon monoxide sometimes form on the surface of the melt-containing crucible just above the initial level of the melt. These formations are avoided by perturbing chemical formation conditions at the region of probable formation. Such perturbations may be provided by a tube through which either a positive pressure of a gas, such as argon, is directed toward the region of probable formation or through which a negative pressure may be applied to perturb the formation conditions.

Abstract: In using a gas torch it is often necessary to maintain a uniform flame. This can be accomplished by maintaining a constant pressure at the torch tip. A pressure transducer is placed at the output of a generator that produces gas by electrolysis for the torch. The transducer indicates changes in the gas pressure by changing resistance. The transducer is coupled to a resistance-capacitance circuit and forms a variable part of the resistance of the circuit. This circuit, in turn, is coupled to the firing gate of a triac which controls the rate of gas disassociation of the electrolytic solution in the gas generator by varying the amount of current fed to the gas generator. When the pressure at the output of the generator varies, the resistance of the pressure transducer changes thereby changing the RC time constant of the resistance-capacitance circuit. Such a change modifies the firing rate of the triac and, therefore, the rate of gas generation and pressure.

Abstract: In making electrically asymmetrical semiconductor devices, it is generally necessary to orient all of the devices into a common polarity at some point in the manufacturing operation. To accomplish this, a magnetic turning chute receives those devices which do not have the desired common polarity and turns them into the common polarity. A helical magnetic field is established in the turning chute by arranging strip magnets into vertical helices around a cylinder. As the devices, which have magnetic properties, progress through the helical field, they are turned by the magnetic force. Further turning impetus is provided by nonmagnetic helical tracks disposed to coincide with the helical magnetic field so that the leads of the devices can slide along the tracks while they move through the chute. Air jets may be used to assist in forcing the devices through the apparatus.

Abstract: To improve the control over resistivity of grown single crystalline ingots, to reduce the turn-around time between growth of successive ingots in a particular crystal grower and to enable recycling of otherwise junk material, a sample of a molten material (the "melt") from which the ingot is to be grown is withdrawn from the crystal grower, cooled, and analyzed. Based on the analysis, controlled additional amounts of the material and/or a dopant impurity are added directly to the melt to restore it to a desired chemical composition. Thus, avoidable is costly and time-consuming cooling of the melt and restarting the system with a completely new charge of material and impurity, and achievable is uniformity of resistivity among the successively grown ingots. Preferably the sample is withdrawn from the melt into a quartz tube which is inserted into the system through a port.

Abstract: A semiconductor wafer from which devices, such as transistors, integrated circuits or the like, are to be formed is gettered. This is done by directing a high energy beam, such as a laser beam, on the surface of the wafer opposite to the surface on which the devices are to be formed. The beam is absorbed by such surface and produces lattice damage and strain in the region of such surface. The wafer is then heated at a temperature and for a time sufficient to produce a dislocation array adjacent to the region of damage. This relieves the strain and attracts mobile defects in the wafer toward the array and away from the surface of the wafer on which the devices are to be formed.The beam may also be directed on the surface of the wafer where the semiconductor devices are to be formed so long as the beam avoids those portions of such surface where the devices are to be formed.