We report the results of a study of poly(etheretherketone) (PEEK) neat resin and APC‐2 carbon fiber composite samples which were processed from the melt and then subjected to a variety of thermal treatments. Wide‐angle x‐ray scattering was used to study the effects of quenching and annealing treatments. For both neat resin and composite, annealing resulted in perfection of the crystalline microstructure. In addition to the crystalline and amorphous scattering usually observed, disorder is frozen‐in by fast cooling after heat treatment. The disordered component is detected as an additional low‐angle scattering peak at 14 degrees, well separated from the crystalline reflections, and is observed in low molecular weight material synthesized in our laboratory, and in commercially available neat resin PEEK and APC‐2 carbon fiber composite samples. When disordered material was subsequently heated above the glass transition, and then cooled very slowly, only the crystalline and amorphous scattering remained. Application of stress also resulted in formation of the disorder in the necked down regions of samples drawn in tension, suggesting that residual stresses may occur as a result of rapid cooling after heat treatment.

No abstract

Strain measurements using x-ray diffraction were performed on irradiated commercial and radiation hardened metal gate CMOS devices in addition to polysilicon gate NMOS devices. I-V curves were taken and Vot and Vi, were separated using the subthreshold slope method for all devices. A correlation has been shown to exist between physical strain relaxation and the electrical properties as a function of radiation dose and recovery. Data shown suggest that the physical response (strain relaxation) in the silicon at the oxide interface is a measure of the type of damage induced and the recovery mechanism. Post radiation measurements of AVit and AVot taken immediately after irradiation support the conclusions of Zekeriya and Ma and Kasama, et al.; compressive stress at the silicon/SiO, interface does reduce radiation damage in the device. "

No abstract

A new millimeter-wave package architecture with supporting electrical, mechanical and material science experiment and analysis is presented. This package is well suited for both individual devices/MMICs and multichip module (NICM) applications. It also has low-loss wideband RF transitions which are necessary to overcome manufacturing tolerances which leads to lower per unit cost. Novel applications of this new packaging architecture which go beyond the standard rec]uirements of device protection include: integration of antennas, compatibility to photonic networks and direct transitions p waveguide systems are described. Techniques for electromagnetic analysis, thermal control and hermetic sealing were explored. 3D electromagnetic analysis was performed using the Finite-Difference Time-Domain (FDTD) algorithm and experimentally verified for millimeter-wave package input and output transitions. Novel multi-material system concepts which allow excellent surface finishes to be obtained (rcxlucing RF loss) and enhance thermal management (AIN, Cu, and diamond thin films) have been investigated. A new approach utilizing block copolymer coatings was employed to hermetically seal packages which met MIL STD-883.