Tohru Satake

Tohru Satake, a prolific inventor hailing from Kanagawa, Japan, has an impressive portfolio of 90 patents to his name. Known for his groundbreaking contributions in the field of electron beam technology, his latest patents include a testing apparatus using charged particles and a device manufacturing method.

In the testing apparatus patent, Satake introduces a novel method for substrate analysis. The system involves irradiating the substrate with primary electrons and subsequently detecting the secondary electrons generated from the substrate using a specialized detector. By placing a reference die on the stage, Satake is able to obtain a pattern matching template image that includes feature coordinates of the reference die. This template image is then used to perform pattern matching with an arbitrary die in a row or column, allowing Satake to determine the feature coordinates of the arbitrary die. In order to correct any misalignment, an angle of misalignment is calculated between the direction of the row or column containing the reference die and the direction of movement of the substrate. Finally, the stage is rotated to correct the misalignment and align the reference die with the direction of movement of the substrate.

Satake's second recent patent focuses on an electro-optical inspection apparatus that utilizes electron beams. By deflecting a primary electron beam through a deflector, the evaluation area on the sample surface is divided into sub-visual fields. In each of these sub-visual fields, secondary electrons containing valuable information about the sample surface are detected using a specialized device. The detecting device consists of multiple unit detectors. Each unit detector includes an area sensor, a bundle of optical fibers with one end coupled to the detection plane of the area sensor, and a fiber optic plate (FOP) coated on the other end of the bundle of optical fibers. The FOP is further enhanced with a scintillator, which allows it to focus the secondary electron beam emitted from the respective sub-visual field. An electromagnetic deflector is used to move the secondary electron beams over the surfaces of the FOPs, enabling efficient capture of images.

Throughout his impressive career, Satake has collaborated with esteemed colleagues, including Nobuharu Noji and Kenji Watanabe. He has worked with prominent companies such as Ebara Corporation and Toshiba (Kabushiki Kaisha Toshiba) to further develop and commercialize his innovative inventions.

Tohru Satake's tireless pursuit of advancements in electron beam technology has undoubtedly left a lasting impact on the field. With his numerous patents and collaborations with prestigious organizations, he continues to push the boundaries of what is possible in the realm of electron beam applications.