The Ha~tme-Fmk ground state potential energy curve for the carbon monoxide molecule is calculated using both the finite difference and the finite basis set methods. The results of calculations performed at ten internuclear separations are reported and a mmparision is made of the calculated potential energy curves over the range of internuclear separations, 1.97C-2.330 og. around the experimental equilibrium value. Potential energy curve constants and spectrascopic consmts are determined.

Surface micromachined metal armatures are commonly used for MEMS applications of which RF-MEMS is the most well known. In most cases metals with a high conductivity, such as aluminum or gold, are used. These metals often have a low melting point and therefore have a low thermal stability and show plastic deformation of the structures at relatively low temperatures (<200 • C). High melting point metals, such as platinum, are expected to show plastic deformation only at higher temperatures which makes them interesting for use as a structural layer in RF-MEMS devices. In this paper, we present a technology to realize suspended platinum structures by means of surface micromachining. An improved lift-off process allows patterning 1 μm Pt films on a polyimide sacrificial layer. A comparison of the characteristics and armature resonance frequencies between RF-MEMS switches with Pt armatures and AlCu 0.5% alloy armatures reveals an increased thermal stability for the former up to at least 250 • C. This enables zero-level packaging of switches at relative high temperatures without affecting their performances. The lower conductivity of Pt compared to AlCu 0.5% does not lead to a significant increase in RF losses. Implementing AlN as a dielectric material, the Pt-based capacitive shunt switches reported in this paper showed lifetimes in excess of 5×10 7 cycles under standard testing conditions.

A series of phenylcarbinols have been evaluated as components of chemically amplified resists used for KrF excimer laser lithography. The character of the carbon atom to which the hydroxyl group is bonded to determines the insolubilization reactions, leading to differences in sensitivity. Resists using tertiary phenylcarbinol, which converts into polymeric compounds, exhibits the highest sensitivity while the resists using primary phenylcarbinol, which cross-links the phenolic resin, has the lowest sensitivity. Properties, such as sensitivity and chemistry, of the resist containing the secondary phenylcarbinol groups lie between those of the primary and tertiary phenylcarbinol containing resists.

We describe how molecular-weight distributions of resist polymers and process control affect lithography for 0.1 µm and below, especially for negative-type resists. There are two main issues for precise critical dimension (CD) control and high resolution in the region: microscopic pattern fluctuation caused by ultrasmall edge roughness in fabricated resist patterns (nano edge roughness); and pattern-size change due to acid diffusion in chemical amplification resists. We have found that nano edge roughness and acid diffusion can be suppressed by controlling the molecular-weight distributions of the base matrix polymers. It is also quite important to control process conditions to achieve high pattern fidelity with molecular-controlled resist materials. Multi-step post baking was applied to minimize the resist pattern deformation before dry etching. We have found that this process can suppress pattern size variations to within 10 nm.

Bisazidobiphenyls have been evaluated as photosensitive compounds of negative resists for i-line phase-shifting lithography. The optical parameters of the bisazidobiphenyl resists such as Dill's A, B, and C parameters, molar absorption coefficients, and quantum yields are measured to select an appropriate bisazidobiphenyl for an i-line negative resist. The quantum yields of bisazidobiphenyls strongly depend on the substituents on the aromatic rings and vary between 0.25 and 0.83. The resist sensitivities are proportional to the product of ε and φ, which means the nitrenes produced from each bisazidobiphenyl have the same reactivity with novolak resin. 2,7-Diazidofluorene (azide 6), which has the largest ε·φ, gives the highest sensitivity. However, the resist using a mixture of azide 6 and 4,4'-diazido-3,3'-dimethoxybiphenyl (azide 1) is subjected to lithographic evaluation because azide 6 has low solubility in the casting solvents. The new resist resolves 0.275-µm line-and-space patterns in 1-µm-thick film when it is exposed with an i-line stepper in conjunction with a phase-shifting mask. The required dose of the new resist for imaging is 240 mJ/cm2.