Lithography focus/exposure control and corrections to improve CDU at post etch step

Autor: Lipkong Yap, Young Ki Kim, Lokesh Subramany, Hong Wei, Karsten Gutjahr, Jie Gao, Ram Karur-Shanmugam, Pedro Herrera, Woong Jae Chung, Joungchel Lee, Chen Li, Anna Golotsvan, Vidya Ramanathan, Mark Yelverton, Kevin Huang, Lester Wang, Jeong Soo Kim, John Tristan, Bill Pierson, Ching-Hsiang Hsu
Rok vydání: 2014
Předmět:
Zdroj: Metrology, Inspection, and Process Control for Microlithography XXVIII.
ISSN: 0277-786X
Popis: As leading edge lithography moves to advanced nodes in high-mix, high-volume manufacturing environment, automated control of critical dimension (CD) within wafer has become a requirement. Current control methods to improve CD uniformity (CDU) generally rely upon the use of field by field exposure corrections via factory automation or through scanner sub-recipe. Such CDU control methods are limited to lithography step and cannot be extended to etch step. In this paper, a new method to improve CDU at post etch step by optimizing exposure at lithography step is introduced. This new solution utilizes GLOBALFOUNDRIES’ factory automation system and KLA-Tencor’s K-T Analyzer as the infrastructure to calculate and feed the necessary field by field level exposure corrections back to scanner, so as to achieve the optimal CDU at post etch step. CD at post lithography and post etch steps are measured by scatterometry metrology tools respectively and are used by K-T Analyzer as the input for correction calculations. This paper will explain in detail the philosophy as well as the methodology behind this novel CDU control solution. In addition, applications and use cases will be reviewed to demonstrate the capability and potential of this solution. The feasibility of adopting this solution in high-mix, high-volume manufacturing environment will be discussed as well.
Databáze: OpenAIRE