Neural Network Based Uniformity Profile Control of Linear Chemical–Mechanical Planarization
نویسندگان
چکیده
In this paper, a neural network based uniformity controller is developed for the linear chemical–mechanical planarization (CMP) process. The control law utilizes the metrology measurements of the wafer uniformity profile and tunes the pressures of different air-bearing zones on Lam linear CMP polishers. A feedforward neural network is used to self-learn the CMP process model and a direct inverse control with neural network is utilized to regulate the process to the target. Simulation and experimental results are presented to illustrate the control system performance. Compared with the results by using statistical surface response methods (SRM), the proposed control system can give more accurate uniformity profiles and more flexibility.
منابع مشابه
Axiomatic Design of a Chemical Mechanical Polishing (CMP) Wafer Carrier with Zoned Pressure Control
Axiomatic Design was used to develop a complete platform for chemical mechanical polishing (CMP) of silicon wafers. A functional requirement of the machine emerging from the axiomatic design process is the control of the wafer-scale polishing uniformity. Mechanisms to maintain control of the uniformity were designed, and integrated into a wafer carrier, which holds the wafer during polishing an...
متن کاملModeling SMA actuated systems based on Bouc-Wen hysteresis model and feed-forward neural network
Despite the fact that shape-memory alloy (SMA) has several mechanical advantages as it continues being used as an actuator in engineering applications, using it still remains as a challenge since it shows both non-linear and hysteretic behavior. To improve the efficiency of SMA application, it is required to do research not only on modeling it, but also on control hysteresis behavior of these m...
متن کاملStatistical Analysis of In-Situ End-Point Detection in Copper Chemical-Mechanical Polishing
This paper presents statistical techniques for analysis in-situ end-point data in Cu CMP. An optical reflectance sensor is employed on a rotary polishing tool to measure the surface re flectance of patterned Cu wafers. Statistical models are developed to determine the surface condition based on the characteristics of the sample reflectance data. A nested variance model is proposed to decouple ...
متن کاملAdaptive Predictive Controllers Using a Growing and Pruning RBF Neural Network
An adaptive version of growing and pruning RBF neural network has been used to predict the system output and implement Linear Model-Based Predictive Controller (LMPC) and Non-linear Model-based Predictive Controller (NMPC) strategies. A radial-basis neural network with growing and pruning capabilities is introduced to carry out on-line model identification.An Unscented Kal...
متن کاملCompression Algorithms for \Dummy Fill" VLSI Layout Data
Dummy fill is introduced into sparse regions of a VLSI layout to equalize the spatial density of the layout, improving uniformity of chemical-mechanical planarization (CMP). It is now well-known that dummy fill insertion for CMP uniformity changes the back-end flow with respect to layout, parasitic extraction and performance analysis. Of equal import is dummy fill’s impact on layout data volume...
متن کامل