Browsing by Author "Vladar, AE"

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Characterization of prototype silicon pitch artifacts fabricated by scanning probe lithography and anisotropic wet etching
(2005-01-01)
Chien, FSS
;
Hsieh, WF
;
Gwo, S
;
Jun, J
;
Silver, RM
Scanning probe lithography (SPL) and anisotropic tetra-methyl ammonium hydroxide (TMAH) etching (SPL+TMAH) were used to fabricate a series of one-dimensional prototype pitch structures on (110)-oriented silicon substrates. Overall lateral dimensions of the test structure are 20 mum x 80 mum. Line scales, consisting of 10-mum-long, 100-nm-tall, and 40-nm-wide lines, are observable by optical and scanning electron microscopy (SEM). Etched features were produced with pitches varying from 100 nm to 8 mum. Large-scale pattern placement errors of the SPL tool have been evaluated by analysis of optical image data obtained with a calibrated optical metrology instrument. Small-scale errors were analyzed in the range of 100 nm to 2 mum using SEM. Sources of placement error are discussed and possible methods for minimizing them are presented. The SPL+TMAH process in conjunction with a closed-loop scan control has the precision necessary for repeatable device prototyping in the nanoscale regime. (C) 2005 American Vacuum Society.
Silicon nanostructures fabricated by scanning probe oxidation and tetra-methyl ammonium hydroxide etching
(2002-06-15)
Chien, FSS
;
Hsieh, WF
;
Gwo, S
;
Vladar, AE
;
Dagata, JA
Fabrication of silicon nanostructures is a key technique for the development of monolithically integrated optoelectronic circuits. We demonstrated that the process of scanning probe microscope (SPM) oxidation and anisotropic tetra-methyl ammonium hydroxide (TMAH) etching is a low-cost and reliable method to produce smooth and uniform silicon nanostructures on a variety of silicon substrates. Etched structures with a pitch of 100 nm, positive- and negative-contrast structures, and features height greater than 100 nm have been produced on bare silicon, and Si3N4-coated and silicon-on-insulator wafers. Evolution of hexagonal pits on two-dimensional grid structures were shown to depend on the pattern spacing and orientation with respect to Si(110) crystal directions. We successfully combined SPM oxidation with traditional optical lithography in a mixed, multilevel patterning method for realizing micrometer-and nanometer-scale feature sizes, as required for photonic device designs. The combination of SPM oxidation and TMAH etching is a promising approach to rapid prototyping of functional nano-photonic devices. (C) 2002 American Institute of Physics.