Implementation of hybrid metrology at HVM fab for 20nm and beyond

Abstract

Metrology tools are increasingly challenged by the continuing decrease in the device dimensions, combined with complex disruptive materials and architectures. These demands are not being met appropriately by existing/forthcoming metrology techniques individually. Hybrid Metrology (HM) -the practice to combine measurements from multiple toolset types in order to enable or improve the measurement of one or more critical parameters -is being incorporated by the industry to resolve these challenges. Continuing our previous work we now take the HM from the lab into the fab. This paper presents the first-in-industry implementation of HM within a High Volume Manufacturing (HVM) environment. Advanced 3D applications are the first to use HM: 20nm Contact etch and 14nm FinFET poly etch. The concept and main components of this Phase-1 Host-based implementation are discussed. We show examples of communication protocols/standards that have been specially constructed for HM for sharing data between the metrology tools and fab host in GLOBALFOUNDRIES, as well as the HM recipe setup and HVM results. Finally we discuss our vision and phased progression/roadmap for Phase-2 HM implementation to fully reap the benefits of hybridization.

Optimizing hybrid metrology: rigorous implementation of Bayesian and combined regression

“…3, the negative log-likelihood, we get a function that is proportional to the negative logarithm of the posterior probability distribution. If we again ignore normalization constants we get the function that serves as the modified χ 2 function (6) Note, that the second term that reflects the prior information acts as a penalty or regularization term, penalizing possible solutions to the inverse problem for measurement tool 1 that are not consistent with the prior information. The function in Eq.…”

“…Since the term hybrid metrology has gained increased significance in the dimensional metrology community outside NIST [5][6][7] we will start this work with a short overview of two of the most common techniques in Section 2, namely the Bayesian approach and combined regression. The measured targets and the generalized parameter sets that describe them are discussed in Section 3 before we give a detailed description of the performed error analysis both for OCD and SEM in Section 4 and their impact on the hybridization in Section 5.…”

Effect of measurement error budgets and hybrid metrology on qualification metrology sampling

“…(8), (9), (14), and (15)], then the equations can be compared using parameters of direct interest to the user. (2) is used to remove the explicit dependence on the Mandel variance from the original and new formulations of the upper and lower limit equations [Eqs.…”

“…(8) and (9) for the original designation of the limits, and Eqs. (8) and (9) for the original designation of the limits, and Eqs.…”

Hybrid metrology universal engine: co-optimization

“…We subsequently discussed the challenges of HM 3 (related to the measurement uncertainty of the source tool) and introduced the Data Modification Parameter (DMP) methodology to resolve some of the issues while demonstrating measurement improvement on 14nm EUV (extreme ultra violet) & NTD (negative tone develop) lithography as well as on 22nm FinFET gate etch applications. These results led to the first-in-industry implementation of HM in HVM for advanced structures such as 20nm contact holes and 14nm FinFET Gate RIE applications 1 .…”