Santa Barbara Research Center

Raytheon Company

Stephen H Propst

Robert P Ginn

Geoffrey A Walter

Joan K Chia

Cathy M Peterson

This invention pertains to a method for processing readout integrated circuits, and to a readout integrated circuit (10) that is processed in accordance with the method. The method includes a first step of providing a plurality of individual readout circuits each having a substrate (12) and at least one layer (14) constructed to have active circuitry that overlies a first surface (12a) of the substrate. Each of the readout integrated circuits has an associated amount of non-flatness or bowing due at least in part to a first force exerted on the substrate by the at least one layer of circuitry. A next step sorts the plurality of readout integrated circuits into a plurality of groups (A, B, C), wherein members of a group have a similar amount of non-flatness. A next step of the method determines, for each group, a thickness of compensating layer (18) and then applies the compensating layer on a second surface (12b) of the substrate so as to exert a second force on the substrate to counteract the first force and to reduce the amount of non-flatness. In a presently preferred embodiment of the invention the step of applying includes a step of sputtering a layer comprised of Si.sub.3 N.sub.4 upon the second surface. The step of sorting includes the steps of operating an interferometer to generate a pattern of fringes for indicating a degree of non-flatness of each of the readout integrated circuits; and counting the fringes and sorting the readout integrated circuits as a function of the number of fringes.

Readout backside processing for hybridization

An infrared window (26) includes a substrate (40) made of a zinc salt composition and an antireflection coating system (42) deposited on the substrate (40). The coating system (42) comprises a first layer (44) of germanium overlying the substrate (40), a second layer (46) of diamond-like carbon overlying the first layer (44), a third layer (48) of germanium overlying the second layer (46), and a fourth layer (50) of diamond-like carbon overlying the third layer (48). Preferably, the germanium layers (44, 48) are in tension and the diamond-like carbon layers (46, 50) are in compression. The germanium layers (44, 48) are preferably deposited by magnetron sputtering and the diamond-like carbon layers (46, 50) are preferably deposited by plasma activated chemical vapor deposition. Silicon may be used in place of the germanium, and graded compositions can be used for the first layer (44) and the third layer (48).

Infrared window protected by multilayer antireflective coating

Infrared transmitting windows having a diamond support are formed by first depositing diamond (14) on a mold (10) comprising a material which can withstand the optimum diamond growth temperatures. A germanium carbide adhesive layer (18) is deposited on the diamond layer Next, ZnSe, ZnS, or other index-matching material (16) is deposited on top of the diamond coating. Finally, the mold is removed. The end product is a diamond/ZnS(e) IR window requiring little or no polishing of diamond surfaces.

Growing community of inventors

Santa Ynez, CA, United States of America

Stephen H Propst