80 research outputs found
Real-time monitoring and control of critical dimensions in Lithography.
Ph.DDOCTOR OF PHILOSOPH
Thermal processing in lithography: Equipment design, control and metrology
Ph.DDOCTOR OF PHILOSOPH
In-situ measurement and control of photoresist processing in lithography
Ph.DDOCTOR OF PHILOSOPH
Advanced process/equipment control for thermal processing in lithography
Ph.DDOCTOR OF PHILOSOPH
Scanning evanescent wave lithography for sub-22nm generations
Current assumptions for the limits of immersion optical lithography include NA values at 1.35, largely based on the lack of high-index materials. In this research we have been working with ultra-high NA evanescent wave lithography (EWL) where the NA of the projection system is allowed to exceed the corresponding acceptance angle of one or more materials of the system. This approach is made possible by frustrating the total internal reflection (TIR) evanescent field into propagation. With photoresist as the frustrating media, the allowable gap for adequate exposure latitude is in the sub-100 nm range. Through static imaging, we have demonstrated the ability to resolve 26 nm half-pitch features at 193 nm and 1.85 NA using existing materials. Such imaging could lead to the attainment of 13 nm half-pitch through double patterning. In addition, a scanning EWL imaging system was designed, prototyped with a two-stage gap control imaging head including a DC noise canceling carrying air-bearing, and a AC noise canceling piezoelectric transducer with real-time closed-loop feedback from gap detection. Various design aspects of the system including gap detection, feedback actuation, prism design and fabrication, software integration, and scanning scheme have been carefully considered to ensure sub-100 nm scanning. Experiments performed showed successful gap gauging at sub-100 nm scanning height. Scanning EWL results using a two-beam interference imaging approach achieved pattern resolution comparable to static EWL imaging results. With this scanning EWL approach and the imaging head developed, optical lithography becomes extendable to sub-22 nm generations
On flexibly integrating machine vision inspection systems in PCB manufacture
The objective of this research is to advance computer vision techniques
and their applications in the electronics manufacturing industry. The research has
been carried out with specific reference to the design of automatic optical inspection
(AOI) systems and their role in the manufacture of printed circuit boards (PCBs).
To achieve this objective, application areas of AOI systems in PCB manufacture
have been examined. As a result, a requirement for enhanced performance
characteristics has been identified and novel approaches and image processing algorithms
have been evolved which can be used within next generation of AOI systems.
The approaches are based on gaining an understanding of ways in which
manufacturing information can be used to support AOI operations. Through providing
information support, an AOI system has access to product models and associated
information which can be used to enhance the execution of visual inspection
tasks. Manufacturing systems integration, or more accurately controlled access to
electronic information, is the key to the approaches. Also in the thesis methods are
proposed to achieve the flexible integration of AOI systems (and computer vision
systems in general) within their host PCB manufacturing environment. Furthermore,
potential applications of information supported AOI systems at various stages of
PCB manufacturing have been studied.
It is envisaged that more efficient and cost-effective applications of AOI
can be attained through adopting the flexible integration methods proposed, since
AOI-generated information can now be accessed and utilized by other processes
The Journal of Microelectronic Research 2005
https://scholarworks.rit.edu/meec_archive/1014/thumbnail.jp
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