In this work, we report metrology solutions using scatterometry Optical Critical Dimension (OCD)
characterization on two advanced CMOS devices: novel n-channel gate-last In0.53Ga0.47As FinFET with
self-aligned Molybdenum (Mo) contacts and p-channel Ge FinFET formed on Germanium-on-Insulator
(GOI) substrate. Key critical process steps during the fabrication of these advanced transistors were
identified for process monitor using scatterometry OCD measurement to improve final yield. Excellent
correlation with reference metrology and high measurement precision were achieved by using OCD
characterization, confirming scatterometry OCD as a promising metrology technique for next generation
device applications. In addition, we also further explore OCD characterization using normal incidence
spectroscopic reflectometry (SR), oblique incidence spectroscopic ellipsometry (SE), and combined SR+SE
technologies. The combined SR+SE approach was found to provide better precision.
KEYWORDS: Germanium, Scatterometry, Transmission electron microscopy, Scanning electron microscopy, Transistors, Metrology, Etching, Front end of line, 3D modeling
In this work, we report the first demonstration of scatterometry Optical Critical Dimension (OCD) characterization on advanced Ge Multi-Gate Field-Effect Transistor (MuGFET) or FinFET formed on a Germanium-on-Insulator (GeOI) substrate. Two critical process steps in the Ge MuGFET process flow were investigated, i.e. after Ge Fin formation, and after TaN gate stack etching process. All key process variations in the test structures were successfully monitored by the floating or fitting parameters in the OCD models. In addition, excellent static repeatability, with 3σ lower than 0.12 nm, was also achieved. The measurement results from OCD were also compared with both Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) measurements. Excellent correlation with both SEM and TEM was achieved by employing OCD characterization, confirming scatterometry OCD as a promising metrology technique for next generation multi-gate transistor with an advanced channel material.
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.