AVS 46th International Symposium
    Manufacturing Science and Technology Group Tuesday Sessions
       Session MS-TuA

Paper MS-TuA1
CD Control Optimization Methodology on Shallow Trench Isolation Substrate for Sub-0.25µm Technology Gate Patterning

Tuesday, October 26, 1999, 2:00 pm, Room 611

Session: Interconnect and Integration
Presenter: H. Gerung, Chartered Semiconductor Manufacturing Ltd., Singapore
Authors: M.H. Fan, Chartered Semiconductor Manufacturing Ltd., Singapore
H. Gerung, Chartered Semiconductor Manufacturing Ltd., Singapore
P. Yelehanka, Chartered Semiconductor Manufacturing Ltd., Singapore
A. Cheng, Chartered Semiconductor Manufacturing Ltd., Singapore
M.S. Zhou, Chartered Semiconductor Manufacturing Ltd., Singapore
C. Chi, Chartered Semiconductor Manufacturing Ltd., Singapore
C.H. Tan, Institute of Microelectronics, Singapore
J. Xie, Institute of Microelectronics, Singapore
Correspondent: Click to Email
The impact of post-Shallow Trench Isolation (STI) Chemical Mechanical Polishing (CMP) on gate critical dimension (CD) control for submicron technology had been studied. The response of the gate CD depends upon STI process scheme whether it is recess (STI lower than active) or elevated (STI higher than active). Two subjects had been studied: first, CD uniformity as the function of STI step height with active and secondly, CD uniformity as the function of the size of the active area. The topology step height and active size affect the resist coating and organic BARC thickness uniformity. BARC thickness uniformity affects the substrate reflectivity, which leads to variation in the effective exposure dose. This dose variation leads to CD swing across the wafer and resulting in non-uniform CD. We used AFM surface scan to study the topographical variations caused by CMP process on different active area size. A new simulation technique using topographical swing curves and CD error contour plot was applied in this work to optimize BARC and resist thickness. Prolith/2 from FINLE was used for process simulation and excellent agreement was found between simulation and experimental results. Better CD control can be achieved by avoiding extreme recessed or elevated STI topology.