Miguel Jiménez, Kiril Ivanov Kurtev, Juan M. Trujillo-Sevilla, Rubén Abrante, Jose Manuel Ramos-Rodríguez, Jan O. Gaudestad
Wave Front Phase Imaging (WFPI), a new wafer geometry technique, is presented, that acquires 16.3 million data points in 12 seconds on a full 300mm wafer, providing lateral resolution of 65μm while holding the wafer vertically. The flatness of the silicon wafers used to manufacture integrated circuits (IC) is controlled to tight tolerances to help ensure that the full wafer is sufficiently flat for lithographic processing. Advanced lithographic patterning processes require a detailed map of the free, non-gravitational wafer shape to avoid overlay errors caused by depth-of-focus issues. For a wafer shape system to perform in a high-volume manufacturing environment, repeatability is a critical measure that needs to be tested. We present WFPI as a…
Guillermo Castro, Kiril Ivanov, Miguel Jiménez,Juan M. Trujillo-Sevilla, Juan Manuel Ramos-Rodríguez, Jan O. Gaudestad.
Wafer overlay errors due to non-flatness and thickness variations of a mask need to be minimized to achieve a very accurate on-product-overlay (OPO). Due to the impact of overlay errors inherent in all reflective lithography systems, EUV reticles will need…
Kiril Ivanov Kurteva, Guillermo Castro Luis, Juan M. Trujillo-Sevilla, Jan O. Gaudestad, Richard van Haren, Leon van Dijk, Ronald Otten
On product overlay (OPO) is one of the most critical parameters for continued scaling according to Moore’s law. Besides the lithography scanner, also non-lithography processes contribute to the OPO performance. For example, processes like etching and thin film deposition can introduce stress, or stress changes, in the thin films on top of the silicon wafers. In general, the scanner Higher Order Wafer Alignment model up to 3rd order (HOWA3) has proven to be adequate to correct for most process-induced wafer distortions. This model is typically used with 28 wafer alignment marks placed across the wafer to correct for more global stress-induced distortions…
Kiril Ivanov Kurtev, Juan M. Trujillo-Sevilla, Guillermo Castro Luis, Miguel Jiméneza, Rubén Abrante, José Manuel Ramos-Rodríguez, Jan O. Gaudestad
On-product overlay (OPO), with its continually shrinking overlay budget, remains a constraint in the continued effort at increasing device yield. Overlay metrology capability currently lags the need for improved overlay control, especially for multi-patterning applications. The free form shape of the silicon wafer is critical for process monitoring and is usually controlled through bow and warp measurements during the process flow. As the OPO budget shrinks, non-lithography process induced stress causing in plane distortions (IPD) becomes a…
Juan M. Trujillo-Sevilla, Rubén Abrante, Miguel Jiménez, Kiril Ivanov Kurtev, Guillermo Castro Luis, Jan O. Gaudestad
The shrinking depth of focus of high numerical aperture immersion microlithography optics requires a tight wafer flatness budget. Bare wafer surface topography variation is a significant part of the focus budget for microlithography. Thus, as the wafer surface quality becomes increasingly important, the metrology to control the surface quality is increasingly challenged1. Advanced lithographic patterning processes require a detailed map of the free, non-gravitational, wafer shape, to avoid overlay errors caused by depth-of-focus issues2. The semiconductor industry has been using interferometry-based techniques for measuring the free form wafer shape of blank silicon wafers for several years1. In this paper we introduce a…
Juan M. Trujillo-Sevilla, Óscar Casanova-González, Alex Roqué-Velasco, Miguel Jesús Sicilia, Javier González Pardo, José Manuel Ramos-Rodríguez, Jan O. Gaudestad
On product overlay (OPO) is one of the most critical parameters for the continued scaling according to Moore’s law. Without good overlay between the mask and the silicon wafer inside the lithography tool, yield will suffer1. As the OPO budget shrinks, non-lithography process induced stress causing in plane distortions (IPD) becomes a more dominant contributor to the shrinking overlay budget2. To estimate the process induced in-plane wafer distortion after cucking…
Juan M. Trujillo-Sevilla, Alex Roqué-Velasco, Miguel Jesús Sicilia, Óscar Casanova-González, José Manuel Rodríguez-Ramos, Jan O. Gaudestad
Wave Front Phase Imaging (WFPI) is a new wafer shape measurement technique that acquires millions of data points in just seconds or less, on a full 300mm silicon wafer. This provides lateral resolution well below 100μm with the possibility of reaching the lens’ optical resolution limitation between 3-4μm…
Juan M. Trujillo-Sevilla, Miriam Velasco-Ocaña, Sergio Bonaque-González, Carolina Belda-Para, and José M. Rodríguez-Ramos
We present a method for evaluating the quality of optical glass using a high-resolution wavefront sensor, the wavefront phase imaging (WFPI) sensor. As shadowgraphy is a widely used method for inspecting striae in optical glass, it does not provide a quantitative metric that represents the potential optical quality of the glass and should be based on the operator’s experience. We compare the proposed method in two experiments…
Ricardo Oliva-García, Sabato Ceruso, José G. Marichal-Hernández and José M. Rodriguez-Ramos
This work introduces a real-time full-resolution depth estimation device, which allows integral displays to be fed with a real-time light-field. The core principle of the technique is a high-speed focal stack acquisition method combined with an efficient implementation of the depth estimation algorithm, …
Juan Trujillo, Álvaro Pérez, Óscar Casanova, Miriam Velasco, Sabato Ceruso, Ricardo Oliva, Óscar Gómez, Javier Martín, Alex Roqué, José Manuel Rodríguez, Jan O. Gaudestad
Wave Front Phase Imaging (WFPI), a new wafer geometry technique, is presented, that acquires 7.65 million data points in 5 seconds on a full 300mm wafer providing lateral resolution of 96µm.