Abstract: The uniformity of solid crystals grown by pulling a seed crystal from a molten charge material in a crucible is increased by eliminating vibration by supporting a housing for the solid crystal on a vibration isolator which rests on a supporting floor. Vibration isolators may also be placed between a crucible lift and rotation mechanism and the supporting floor. The crystal pull head for pulling the seed crystal also can be isolated from the remainder of the apparatus by vibration isolators.

Abstract: A crystal growing system has a plurality of crystal growing stations which are each comprised of a crucible, furnace, vacuum chambers and related equipment which is continuously used during the actual crystal growing process. A central process control console is connected to each crystal growing station so that growing parameters for all stations can be controlled from a single location. A common server unit services all crystal growing stations. The server unit is movable so that it can be positioned at each station both prior to initiating crystal formation and subsequent to completing crystal formation in order to service the station before and after the crystal growing operation. The server unit comprises a movable support structure which can be rolled along a set of tracks to be positioned sequentially adjacent to each station. The server unit includes a main hoist constructed to move a receiving chamber, either alone or together with a transition chamber.

Abstract: A puller apparatus for a Czochralski crystal puller system is provided which includes a primary puller chuck and a secondary puller chuck. The primary puller chuck is attached to a seed crystal. The secondary puller chuck is shaped to enclose and retain a portion of a growing crystal so that the growing crystal can be pulled by the secondary puller chuck.

Abstract: The pull head of a Czochralski crystal puller is mounted on a frame which is supported independently from the crystal puller receiving chamber. In particular, the pull head is mounted on a rigid frame which is supported by the same surface that supports the melt charge crucible. The pull head thereby can be aligned relative to the rigid frame, rather than to the receiving chamber, and can be accurately aligned with the crucible rotation axis and positioned in order to insure that its rotation axis is vertical. In one embodiment, the pull head is mounted on a plate which engages alignment pins attached to the rigid frame. The alignment pins insure proper alignment of the pull head relative to the frame. When the receiving chamber is raised to allow the crystal to be removed, the plate is engaged by the receiving chamber and lifted off the alignment pins so that the pull head moves with the receiving chamber.

Abstract: An enclosing structure extends into a transition zone of a crystal growing system through which the growing crystal is pulled. One or more independent temperature control devices are secured to the inside surface of the enclosing structure, which control devices sense crystal temperature and supply to, or extract heat from, the crystal so that a carefully-controlled thermal gradient can be established either radially or longitudinally in the crystal. The temperature control devices may include temperature sensors that provide temperature information to a central control device connected to each temperature control device. The enclosing structure may have a hollow wall structure through which a heat exchange fluid, such as water, is passed to extract heat from the transition chamber and crystal. The temperature control apparatus may also be segmented so that each segment can be controlled independently of the remaining segments thereby permitting independent control to be effected at different crystal areas.

Abstract: Orbital oscillations of the crystal ingot suspended in a cable in a Czochralski crystal puller are damped by mechanically connecting a high-temperature conductor to the ingot and generating a magnetic field in the vicinity of the conductor. The magnetic field induces an eddy current in the conductor when the ingot moves. The eddy current then interacts with the magnetic field to damp motion of the ingot. In one embodiment, the magnetic field generator is moved as the ingot grows to maintain the magnetic field in the vicinity of the conductor. In another embodiment, the strength of the magnetic field is adjusted dependent on the amplitude of the oscillations to conserve power.

Abstract: A signal conditioning unit receives index and data signals from a rotary incremental encoder, and attenuates the pulse-to-pulse jitter of the data signal by passing the data signal through an AND gate having at least two of its inputs tied to the data signal to provide a jitter attenuated data signal. Zero-delay jitter riding on the index signal is attenuated by ANDing together the index signal and the jitter attenuated data signal to provide a jitter attenuated index signal. The jitter attenuated index signal is then processed to extend the active state of the signal to match the duration of the active state of the index signal, and thus provide a synthesized jitter attenuated index signal. To account for the propagation/processing delay associated with extending the active duration of the jitter attenuated index signal, the jitter attenuated data signal is delayed to provide the proper timing relationship between the processed jitter and index signals.