KEYWORDS: Metrology, Diffractive optical elements, Optical properties, Etching, Inspection, Scatterometry, Semiconducting wafers, Overlay metrology, Back end of line, Front end of line
Persistently shrinking design rules and increasing process complexity require tight overlay control thereby making it imperative to choose the most suitable overlay measurement technique and complementary target design. In this paper we describe an assessment of various target designs from FEOL to BEOL on 20-nm process. Both scatterometry and imaging based methodology were reviewed for several key layers on A500LCM tool, which enables the use of both technologies. Different sets of targets were carefully designed and printed, taking into consideration the process and optical properties of each layer. The optimal overlay target for a given layer was chosen based on its measurement performance.
Requalifying semiconductor photomasks remains critically important and is increasingly challenging
for 20nm and 14nm node logic reticles. Patterns are becoming more complex on the photomask,
and defect sensitivity requirements are more stringent than ever before. Reticle inspection tools
are equally important for effective process development and the successful ramp and sustained
yield for high volume manufacturing. The inspection stages considered were: incoming inspection
to match with Mask Shop Outgoing result and to detect defects generated during transport;
requalification by routine cycle inspection to detect Haze and any other defects; and inspection by
in-house or Mask shop at the post cleaning. There are many critical capability and capacity factors
for the decision for best inspection tool and strategy for high volume manufacturing, especially
objective Lens NA, wavelength, power, pixel size, throughput, full-automation inspection linked
with Overhead Transport, algorithm application, engineering application function, and inspection
of PSM and OMOG . These tools are expensive but deliver differentiated value in terms of
performance and throughput as well as extendibility. Performing a thorough evaluation and
making a technically sound choice which explores these many factors is critical for success of a
fab. This paper examines the methodology for evaluating two different photomask inspection
tools. The focus is on ensuring production worthiness on real and advanced product photomasks
requiring accurate evaluation of sensitivity, throughput, data analysis function and engineering
work function on those product photomasks. Photomasks used for data collection are production
reticles, PDM(Program defect Mask), SiN spray defect Reticle which is described that evaluates
how the tools would perform on a contaminated plate.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.