The semiconductor industry uses a large amount of perfluoro compounds (PFCs), and their impact on global warming has become a major environmental concern. In the semiconductor industry, PFC are used to periodically remove deposits from the chamber walls of chemical vapor deposition (CVD) reactors after film deposition. These chamber clean processes account for typically 50%–70% of the PFC usage in a semiconductor wafer fabrication site, the rest being mainly used for wafer-etching processes. With a conventional parallel plate radio frequency (rf) plasma reactor, the PFC gas utilization is incomplete and a large fraction of unreacted gas can be emitted in the atmosphere. This paper describes a microwave plasma source that provides as high as 99.9% utilization removal efficiency (URE) of the reactant gas (NF3) during chamber clean. This technology brings the million metric tons carbon equivalent (MMTCE) of a chamber clean to negligible levels and also enhances the chamber clean efficiency and the system throughput. Here we review the requirements for the manufacturability of a remote plasma clean process. Gaseous Fourier transform infrared and quadrupole mass spectroscopy techniques have been used to characterize the clean process, the by-products of the reaction, and the efficiency in reducing the MMTCE of CVD chamber cleans.

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Traditional semiconductor manufacturing relies on a fixed process-recipe combined with a classical statistical process control that is used to monitor the production process. Leading-edge manufacturing processes require higher levels of precision and accuracy, which necessitate the use of tighter process control. Advanced Process Control (APC) is becoming a critical component to improve performance, yield, throughput, and flexibility of the manufacturing process using run-to-run, wafer-to-wafer, within wafer and real-time process control. The complexity of device manufacturing process as well as the strong coupling effect of several input parameters on the final process outputs prohibit the use of a classical single variable feedback control method. Therefore, multivariate, model-based APC system is developed in conjunction with feed-forward and feedback mechanisms to automatically determine the optimal recipe for each wafer based on both incoming wafer and tool state properties. The APC system uses wafer metrology, process models and sophisticated control algorithms to provide dynamic fine-tuning of intermediate process targets that enhance final device targets. The design of the APC system enables scalable control solutions across a single chamber, a process tool, multi-tools, a process module and multi-process modules using similar building blocks, concepts and algorithms.

A nitrogen-free (N-free) dielectric anti-reflective coating (DARC®) was cost-effectively developed in a plasma-enhanced chemical vapor deposition (PECVD) reactor to eliminate the 193nm resist poisoning interaction caused when N2O is used as a precursor [1]. Although it was found that even a N-free ARC could poison sensitive 193nm resists with –OH radicals [2], which either exist inherently in the ARC or result from H2O absorption by the ARC surface, the current investigation has revealed that it was possible to minimize resist poisoning. Our investigation showed that compressive film stress directly correlates to H2O resistance. Therefore, it was possible to greatly improve the ARC resistance to H2O absorption by creating and maintaining a process regime that makes the ARC film dense. The dense ARC film demonstrated promising lithography performance with minimal resist poisoning as well as excellent shelf life and O2-ashing resistance. This paper explores the N-free DARC material, its development, lithographic integration results and implementation in a production environment to eliminate 193nm resist poisoning.