A cluster system controls the interface properties of the films that deposit or grow on a silicon substrate. The system comprises a plurality of horizontal quartz chamber or tubes each of which can hold a large quantity of wafers, a transfer chamber and a load/unload chamber. Several process steps can be executed sequentially in different tubes without intermediate exposure to ambient air. A transfer chamber connects them and allows wafer transportation from one tube to another in an absolute controlled UHV environment which limits any contamination such as H.sub.2 O, to less than a monolayer level. In addition, each tube can be pumped down to UHV pressure regime to avoid further cross contamination between tubes or particle generation. Since some of the process requires elevated temperature, all wafers are placed vertically on the quartz boat to prevent any wafer sagging as in a vertical furnace. Furthermore, before any wafers are placed into the transfer chamber, they are loaded into a load/unload chamber, which is the sole connection to the ambient air, to be purged and pumped so as to minimize particles and contamination.

An xDSL communication system having a reduced number of digital filter coefficients. The full-length equalizer channel impulse response is truncated by first selecting a subset of contiguous filter samples followed by windowing and convolution with a time domain representation of a frequency domain filter. The result is a shorter equalizer having fewer coefficients so as to improve data transmission rate.

A substrate fabrication system is provided which includes a buffer station located inline between a front docking port and a loadlock chamber, the buffer station being operatively joined with a front handling chamber. Preferred embodiments employ a buffer station having a rack with reduced pitch, or relative spacing between shelves. Additional embodiments provide variable pitch end effectors as part of the disclosed fabrication system. Methods of fabricating wafers by quickly transferring them to purgeable buffer stations upon wafers arriving at a docking port are also provided.

A high-speed wafer-processing apparatus and method that employs a vacuum chamber having at least two wafer transport robots and a process station. The vacuum chamber interfaces with a number of single-wafer load locks that are loaded and unloaded one wafer at a time by a robot in atmosphere. Four load locks are sized to allow for a gentle vacuum cycling of each wafer without significant pumpdown delays. The robots in the vacuum chamber move wafers sequentially from one of the load locks to a process station for processing and then to another one of the load locks for unloading by the atmospheric robot.

A receiver frame loads and unloads a batch of semiconductor wafers onto wafer holders in a wafer boat. The wafer holders extends continuously about the perimeter of an overlying wafer. The receiver frame is provided with a plurality of supporting arms which are immovably mounted to a vertically extending structure. The supporting arms are coaxially aligned and vertically spaced in a manner corresponding with the spacing of the wafer holders in the wafer boat. Each supporting arm is configured to be accommodated below a support ring, with its distal end extending to align with the center region of the wafer holder. The distal end of each supporting arm is provided with at least three support pins to support a wafer vertically spaced above a wafer holder. To load wafers onto the wafer holders, after placing the wafers upon the support pins, the wafer holders are moved above the support pins so that the wafer holders contact and lift the wafers off the support pins.