Resist resolution

In addition to good sensitivity, issues for X-ray resist materials are analogous to those of optical and e-beam resists resolution, contrast, etch resistance, thermal stability, and adhesion. To stay competitive with e-beam and even optical lithography, X-ray lithography must have a resolution performance better than 0.5 p,m. An extensive list of X-ray resist properties has been collected in the literature (83, 116, 121). 

The design of the most advanced microelectronic devices now requires with sub-half micron dimensions. Photo, electron beam and x-ray lithographies are all candidates for patterning at such resolution. Resist resolution, along with relief image wall profiles and contrast must be improved and controlled in order for the fabrication of such devices to become practical. 

As for quantitative prediction concerning crosslinking negative resist resolution, no theories are available except relationships between polydispersivity (Mw / Mn) and contrast (JT). Charlesby showed... 

Resolution is perhaps the most important parameter in lithography, which drives the whole industry forward. However, the definition of resist resolution is elusive at least in part due to the fact that the resolution depends heavily on exposure tools also. When the resolution is mentioned, NA of the stepper lens and exposing wavelength should accompany in photolithography as the resolution (R) is proportional to the exposing wavelength (A) and inversely proportional to NA of the lens R=k1A/NA. 

Poly(l-butene sulfone) resist has been widely used in photomask manufacture since the 1970s and 1980s because it affords resolution down to about 500 nm (on the mask). It is marketed under the commercial name PBS and was extremely successful during this time. However, the performance of the resist in terms of etch resistance, resolution, and critical dimension linearity and uniformity was found to be inadequate as the industry migrated to much smaller critical dimensions that required dry etch processing of the photomask Cr. ... 

Advanced Resist Processing and Resist Resolution Limit Issues... 

These resistance resolution requirements dictate use of special signal conditioning techniques to cancel the lead and contact resistance of the RTD element (Fig. 18.22). The circuit depicted in Fig. 18.22 is a variation of a 4-wire ohmmeter. Most RTDs are manufactured with four leads to be compatible with such circuits. 

With the system shown, a resistance resolution of 1 part in 100,000 is possible at 1 kHz, which degenerates to 1 part in 1000 at 1 Hz. System noise and detector inadequacies account for loss in resolution. Capacitance... 

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