(311f) Run-to-Run Control across Multiple Cycles for a Low Selectivity Area-Selective Aluminum Oxide Deposition Reaction on Silicon Oxide and Silicon Hydride Surfaces

Semiconductor manufacturing processes continue to become more and more complicated as Moore’s Law continues to hold true [4]. To fabricate these complex, 3D devices, a silicon substrate may go through upwards of 500 process steps to create a single product [2]. These steps typically consist of a combination of bulk deposition of a material, photolithography to form the desired structure, and etching to remove the undesired material. Recently, a new fabrication method known as “Area-Selective Atomic Layer Deposition” (ASALD) has received attention due to its ability to eliminate the photolithography and etching steps, reducing the required number of process steps drastically. This comes by taking advantage of the patterns in an underlying layer where the substrate has a Non-Growth Area with a low deposition rate and a Growth Area with a high deposition rate [5]. Thus, deposition will selectively occur on the Growth Area. However, due to its sensitivity to the selectivity of the ASALD reaction between the Growth and Non-Growth Areas, process disturbances can have large impacts on the feasibility of ASALD processes. If there is no stable process control structure, then the implementation of ASALD reactions may result in wasted resources and lower manufacturing efficiency rather than increased quality.

This work investigates the application of ALE cycles as a control action in between ASALD cycles. Specifically, the reaction to be examined is the deposition of Al₂O₃ on SiOH as the Growth Area with SiH as the Non-Growth Area [3]. This ASALD reaction has a lower selectivity compared to other explored ASALD reactions, which requires it to have some form of process control to ensure stability in its operation. By using ex-situ run-to-run methods that measure the weight of the deposited layer, a process controller that uses an ALE cycle as a discrete response to control the selectivity of the ASALD cycle can be implemented [1]. This process would allow for robust operation of ASALD reactions in general, as it would reduce the effects of process disturbances that reduce the selectivity of the ASALD reactions.

• Moyne, J., del Castillo, E., Hurwitz, A. M., 2018. Run-to-Run Control in Semiconductor Manufacturing. CRC Press
• Richard, C., 2023. Understanding Semiconductors: A Technical Guide for Non-Technical People. Apress, Berkeley, CA.
• Roy Chowdhuri, A., Takoudis, C. G., Klie, R. F., & Browning, N. D. (2002). Metalorganic chemical vapor deposition of aluminum oxide on Si: evidence of interface SiO 2 formation. Applied physics letters, 80(22), 4241-4243.
• Shalf, J., 2020. The future of computing beyond Moore’s Law. Phil. Trans. R. Soc. A.37820190061
• Wang, H., M. Tom, F. Ou, G. Orkoulas and P. D. Christofides, ''Multiscale Computational Fluid Dynamics Modeling of an Area-Selective Atomic Layer Deposition Process Using a Discrete Feed Method,'' Dig. Chem. Eng., 10, 100140, 2024.