Bernd Szyszka

CMOS-compatible purely capacitive interfaces for high-density in-vivo recording from neural tissue

CMOS-based neural tissue in-vivo recording chips with a purely capacitive interface are presented with 256 sites resp. 256 recording channels. A 3D post-CMOS ALD-based process allows to provide a highly efficient sensor dielectric and to realize a protective insulation layer for the non-active part of the fabricated devices. A simple interconnect-efficient sensor array topology is used. Electrical characterizations and in-vivo measurements with biological content reveal proper operation of the presented approach.

Three dimensional ALD of TiO 2 for in-vivo biomedical sensor applications

Titanium dioxide, known as a high-k biocompatible dielectric transducer material, is processed by means of ALD and applied to a 3D structure with dimensions typical for multi-site multi-channel in-vivo neural interfaces. High uniformity, high areal capacitance, and in particular low leakage current densities are achieved within a sufficiently wide operation voltage window. The results demonstrate the suitability of this process to provide dielectric interfaces for 3D biomedical applications.

Protective coatings for durability enhancement of optical surfaces

Abstract Thin films and coatings are a backbone for optical applications in industry, medical equipment, automotive, building and communication sectors, as well as in household and consumer products. Thin films applied on the substrate, such as glass or polymers, for example, polycarbonate, enable the substrate to gain beneficial functions which can improve its energy saving properties, optical transparency, and operational life span. This chapter focuses on the application of protective coatings on optical systems with an emphasis on the methods for characterizing and optimizing the coatings quality, in particular their mechanical and tribological performance, and environmental stability.

Assessment of a Chip Backside Protection

Security-sensitive integrated circuits (ICs) are equipped with various hardware and software countermeasures which make them more secure. However, the chip backside is still exposed, and a proper countermeasure which is able to protect the ICs against physical and optical attacks through the silicon backside is required. This work presents the development, realization, and evaluation of a countermeasure concept for the IC backside against attack through the silicon backside, which is opaque to infrared light. This protection concept is able to detect any physical tampering on the IC backside. The IC backside, which is protected with an optically active layer and IC electronics, is used to create a signal to indicate a violation of the back surface. The advantages and drawbacks of the method are discussed. An assessment of the attacks through the chip backside, available countermeasures against them, and the properties of a proper protection structure are included.

Graphene assisted effective hole-extraction on In2O3:H/CH3NH3PbI3 interface: Studied by modulated surface spectroscopy

Charge separation in CH3NH3PbI3 (MAPbI3) films deposited on a hydrogen doped indium oxide (In2O3:H) photoelectrode was investigated by modulated surface photovoltage (SPV) spectroscopy in a fixed capacitor arrangement. It was found that In2O3:H reproducibly extracts photogenerated-holes from MAPbI3 films. The oxygen-plasma treatment of the In2O3:H surface is suggested to be a reason for this phenomenon. Introducing graphene interlayer increased charge separation nearly 6 times as compared to that on the In2O3:H/MAPbI3 interface. Furthermore, it is confirmed by SPV spectroscopy that the defects of the MAPbI3 interface are passivated by graphene.

Simulation des reaktiven Magnetron- Sputterprozesses in Inline-Anlagen

Das reaktive Magnetronsputtern von optischen Schichten stellt eine industriell etablierte Beschichtungstechnologie dar, die sich durch hohe Produktivitat und exzellente Schichteigenschaften auszeichnet. Dennoch besteht Bedarf far weitreichende Optimierungen. Probleme resultieren vor allen aus den folgenden Bereichen: Schlechte Ubertragbarkeit von Laborergebnissen auf Produktionsanlagen, hohe Kosten durch aufwandige Technologie und geringe Beschichtungsraten sowie eingeschrankte Produktqualitat bei Spezialanwendungen, wie zum Beispiel der Festmas- anstelle der Bandmas-Beschichtung von Architekturglas. Gerade die wirtschaftlich hoch attraktive Prozessfuhrung im Bereich instabiler Prozessparameter („Transition Mode“) erweist sich als industriell nur sehr schwer umsetzbar.