Direct write applications

Another method for minimizing the proximity effect involves changing the electron beam acceleration potential from the 10 to 20 KV range that is typically used in direct write applications. L. D. Jackel and co-workers have proposed that increasing the acceleration potential to 100 KV will minimize the need for proximity corrections as the backscattered electrons will be averaged over a larger area (2). While this approach may reduce the effect of backscattered electrons, it will also significantly reduce the resist sensitivity since a smaller number of electrons will be deposited in the resist at 100 KV. 

Two dry film resists designed to address the needs of the laser direct-write applications for PCBs and PWBs are Riston LUV and Riston LV , developed by Dupont, and are reported to be sensitive to the UV and visible emission of argon lasers. In particular, Riston LV is based on the principles of dye-sensitized polymerization (presented earlier). 

Precursor polymers may be applicable in direct writing applications (5). That is, they will be convertable, either by UV, X-ray or electron beam radiation from an insulating phase to a conducting phase in one step. Reduction in processing steps is of interest in any lithographic process. 

Pique, A. Chrisey, D. B. 2001. Direct-write electronics for rapid prototyping applications. In Sensors, Electronics and Integrated Power Sources. Academic Press, New York. 

Although e-beam lithography can give excellent spatial control of functional microdomains, this direct-write patterning process is not time-efficient for large-area integration of functional devices. Techniques for rapid patterning of functional nanostructures are thus needed for real-time applications. Ober et al. [106-108] have successfully developed a novel block copolymer... 

Grzybowski, B.A., Haag, R., Bowden, N., Whitesides, G.M., Generation of micrometer-sized patterns for microanalytical applications using a laser direct-write method and microcontact printing. Anal. Chem. 1998, 70(22), 4645-4652. 

Thermal laser CVD involves the same chemical deposition processes that occur in thermal CVD. It, therefore, is applicable to depositing the same types of materials that the thermal CVD process does. Its major application is the direct writing of thin films in semiconductor processing. 

The research in glass modification by use of short laser pulses is driven by scientific interest and their applications have been demonstrated for the formation of three dimensional optical memories and multicolour images , the direct writing of waveguides, waveguide couplers and splitters, waveguide optical amplifier, and optical gratings" ". 

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