Abstract: An epitaxial film deposition system has a low vacuum venturi pump for initially partially purging the system of toxic gases, and a high vacuum turbo-molecular pump to further sharply reduce the pressure to maximize toxic gas purging along with the detection of any slight leaks of toxic gases in the system. A source gas mixing manifold has an array of gas feed lines layed out in a rectangular array for forwarding the gases to the reactor furnace, wherein each feed line has an equal path length between each run valve of the mixing manifold and the reactor to minimize switching transient variations.

Abstract: A boat, carrying wafers to be processed, is pushed into a furnace by a substantially elongated and cantilevered actuator arm having a lug that pushes by first rotating the arm, to cause the lug to traverse a vertical rod attached to against a plate affixed to the boat. The boat is later pulled out of the furnace the boat, and thereafter pulling on the arm to enable the lug to pull against the vertical rod to withdraw the boat. Reliable operation is attained regardless of sagging of the actuator arm relative to the boat.

Abstract: A projection system derived from certain solid geometrical properties using two aperture plates bearing arrays of holes with well defined spacing projects radiation from diverse sources such as electromagnetic radiation, visible and invisible light radiation, discrete particles, X-rays, gamma rays, charged and uncharged particles, as a multi-dot radiation image pattern onto a distant target, overcoming the enormous intensity losses inherent in prior art for pin hole projection of test patterns. The source angular emission function may be of nearly any type, from omni-directional (perfectly diffuse) to uni-directional. Such dot patterns are suitable for evaluating imaging systems as well as the critical operating parameters of mapping spectrometer sensors. The lensless projection system is capable of superimposing radiation source rays from every hole in the first aperture plate onto each image dot at the focal plane with dramatic increase in intensity of the projected image.