摘要:
A method of controlling deposition quality of line-of-sight and target surfaces in a plasma-enhanced chemical vapor deposition apparatus. Adhesion and integrity of deposited film on the surfaces is improved by one or more of (1) avoiding differential thermal expansion of the film and the underlying surfaces, (2) controlling geometry of the surfaces to eliminate edges which generate stress in the deposited film, and (3) using material for the surfaces which provides strong adhesion of the deposited film. For instance, differential thermal expansion can be avoided by maintaining the surfaces at a substantially constant temperature such as ambient temperature.Apparatus for controlling deposition quality of line-of-sight and target surfaces in a plasma-enhanced chemical vapor deposition apparatus. The apparatus includes a plasma shield having a line-of-sight surface and a plasma target having a target surface. The line-of-sight surface defines a bore through the plasma shield and is located out of direct contact with a plasma stream, such as oxygen, which passes from a plasma chamber, through the bore, and into a reaction chamber. A semiconductor specimen is mounted on a support in the reaction chamber. The target surface surrounds the specimen. The line-of-sight and target surfaces are maintained at a substantially constant temperature by circulating a fluid medium through fluid passages in the plasma shield and plasma target. The plasma target can include a removable plate having the target surface on one side thereof. The plasma shield can include a removable gas ring for ejecting gas, such as SiH.sub.4, into the bore.
摘要:
A method of controlling deposition quality of line-of-sight and specimen surrounding surfaces in a plasma-enhanced chemical vapor deposition apparatus. Adhesion and integrity of deposited film on the surfaces is improved by one or more of (1) avoiding differential thermal expansion of the film and the underlying surfaces, (2) controlling geometry of the surfaces to eliminate edges which generate stress in the deposited film, and (3) using material for the surface which provides strong adhesion of the deposited film. For instance, differential thermal expansion can be avoided by maintaining the surfaces at a substantially constant temperature such as ambient temperature.
摘要:
A seismic receiver is provided for measuring seismic signals transmitted through the earth and received in a well borehole. A reversible electrical motor drives a harmonic drive reducer which amplifies the torque provided to drive a ball screw. The ball screw moves linearly along the axis of the well borehole to control the extension of a clamp arm into and out of an extended position in contact with subsurface earth adjacent the well borehole. A releasable electric clutch is provided so the receiver is retrievable in the event of a power failure while the clamp arm is extended.