Paper
1 August 1991 Mix-and-match lithography for half-micron technology
Warren W. Flack, David H. Dameron
Author Affiliations +
Abstract
Half-micron lithography for a production environment is not considered realistic with currently available lithography tools. While optical steppers have high wafer throughputs, they do not have sufficient process latitude at half-micron geometries. In contrast, advanced technologies with sufficient capabilities for half-micron processing such as direct-write e-beam and x-ray lithography are extremely expensive and have low effective throughputs. A mix-and- match lithography approach can take advantage of the best features of both types of systems by sing an optical stepper for noncritical levels and an advanced lithography system for critical levels. In order to facilitate processing of a triple level metal half-micron CMOS technology, a mix-and-match scheme has been developed between a Hitachi HL-700 D e-beam direct write system and an Ultratech 1500 wide-field 1x stepper. The Hitachi is used to pattern an accurate zero or registration level. All critical levels are exposed on the Hitachi and aligned back to this zero level. The Ultratech is used to align all other process levels which do not have critical targets that are placed on subsequent process levels. The mix-and-match approach is discussed, and optical to e-beam as well as e-beam to optical alignment results from seven production lots are presented. The linear alignment error components X translation, Y translation, rotation and magnification are extracted and analyzed to determine their source. It was found that a simple adjustment improved the registration capabilities of these two lithography tools by reducing the X translation, Y translation and rotation standard deviations by a factor of two or more, while greatly reducing the magnification errors between the two tools.
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Warren W. Flack and David H. Dameron "Mix-and-match lithography for half-micron technology", Proc. SPIE 1465, Electron-Beam, X-Ray, and Ion-Beam Submicrometer Lithographies for Manufacturing, (1 August 1991); https://doi.org/10.1117/12.47353
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Cited by 1 scholarly publication.
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KEYWORDS
Lithography

Optical alignment

Semiconducting wafers

Distortion

Electron beam lithography

Wafer-level optics

X-ray lithography

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