Development of graphene process control by industrial optical spectroscopy setup

O. Fursenko; M. Lukosius; G. Lupina; J. Bauer; C. Villringer; A. Mai

doi:10.1117/12.2269603

26 June 2017 Development of graphene process control by industrial optical spectroscopy setup

O. Fursenko, M. Lukosius, G. Lupina, J. Bauer, C. Villringer, A. Mai

Proceedings Volume 10330, Modeling Aspects in Optical Metrology VI; 1033017 (2017) https://doi.org/10.1117/12.2269603
Event: SPIE Optical Metrology, 2017, Munich, Germany

Abstract

The successful integration of graphene into microelectronic devices depends strongly on the availability of fast and nondestructive characterization methods of graphene grown by CVD on large diameter production wafers [1-3] which are in the interest of the semiconductor industry. Here, a high-throughput optical metrology method for measuring the thickness and uniformity of large-area graphene sheets is demonstrated. The method is based on the combination of spectroscopic ellipsometry and normal incidence reflectometry in UV-Vis wavelength range (200-800 nm) with small light spots (~ 30 μm²) realized in wafer optical metrology tool. In the first step graphene layers were transferred on a SiO₂/Si substrate in order to determine the optical constants of graphene by the combination of multi-angle ellipsometry and reflectometry. Then these data were used for the development of a process control recipe of CVD graphene on 200 mm Ge(100)/Si(100) wafers. The graphene layer quality was additionally monitored by Raman spectroscopy. Atomic force microscopy measurements were performed for micro topography evaluation. In consequence, a robust recipe for unambiguous thickness monitoring of all components of a multilayer film stack, including graphene, surface residuals or interface layer underneath graphene and surface roughness is developed. Optical monitoring of graphene thickness uniformity over a wafer has shown an excellent long term stability (s=0.004 nm) regardless of the growth of interfacial GeO₂ and surface roughness. The sensitivity of the optical identification of graphene during microelectronic processing was evaluated.

This optical metrology technique with combined data collection exhibit a fast and highly precise method allowing one an unambiguous detection of graphene after transferring as well as after the CVD deposition process on a Ge(100)/Si(100) wafer. This approach is well suited for industrial applications due to its repeatability and flexibility.

Citation Download Citation

O. Fursenko, M. Lukosius, G. Lupina, J. Bauer, C. Villringer, and A. Mai "Development of graphene process control by industrial optical spectroscopy setup", Proc. SPIE 10330, Modeling Aspects in Optical Metrology VI, 1033017 (26 June 2017); https://doi.org/10.1117/12.2269603

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

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.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available