K. Kucharski

Silicon ultra fast cameras for electron and γ sources in medical applications

Abstract SUCIMA (Silicon Ultra fast Cameras for electron and γ sources In Medical Applications) is a project approved by the European Commission with the primary goal of developing a real time dosimeter based on direct detection in a Silicon substrate. The main applications, the detector characteristics and technologies and the data acquisition system are described.

Temperature enhancement of terahertz responsivity of plasma field effect transistors

Temperature dependence of THz detection by field effect transistors was investigated in a wide range of temperatures from 275 K down to 5 K. The important increase of the photoresponse following 1/T functional dependence was observed when cooling from room temperature down to 30 K. At the temperatures below ∼30 K, the THz response saturated and stayed temperature independent. Similar behavior was observed for GaAs, GaN, and Si based field effect transistors. The high temperature data were successfully interpreted using recent theory of overdamped plasma excitation in field effect transistors. The low temperature saturation of the photoresponse was tentatively explained by the change of the transport regime from diffusive to ballistic or traps governed one. Our results clearly show that THz detectors based on field effect transistors may improve their responsivity with lowering temperature but in the lowest temperatures (below ∼30 K) further improvement is hindered by the physics of the electron transport ...

Hybrid active pixel sensors and SOI inspired option

Abstract Two novel pixel sensor concepts for future linear collider applications are presented in this paper: a hybrid pixel sensor characterized by a layout improving the single point resolution and a monolithic detector inspired by silicon on insulator (SOI) technology. The results of charge collection studies for the first prototypes of hybrid pixel sensors with interleaved pixels are reported and the new detector test structures are introduced. The technology and the readout architecture design for SOI sensors are also discussed.

Monolithic active pixel sensor realized in SOI technology—concept and verification

The paper presents the concept and the verification of a novel silicon monolithic active pixel detector realized in the SOI technology. The reliability and the basic electrical characteristics of the sensor are studied and the sensor sensitivity to the ionising radiation is investigated in details.

Development of monolithic active pixel sensor in SOI Technology fabricated on the wafer with thick device layer

Monolithic active pixel detectors fabricated in SOI (Silicon On Insulator) technology are novel sensors of ionizing radiation, which exploit SOI substrates for the integration of readout electronics and a pixel detector. The fully depleted sensing diode has been manufactured under buried oxide (BOX) while read-out circuitry occupies upper silicon layer (‘device layer’). The development of the SOI detectors of ionizing radiation was started as a part of the SUCIMA project. During the project, it was proved that a monolithic SOI detector is a viable option for high-energy physics and medicine. The early prototypes suffered from significant leakage currents and soft breakdowns. These effects limited yield of production. Moreover, the p-wells (formed within the device layer and extended to the interface with the BOX), caused some local potential wells below the BOX at the top of depleted sensor area reducing the effective charge collection efficiency. The use a thicker device layer and optimized technology appeared to be a remedy.

Fully depleted monolithic active pixel sensor in SOI technology

An active pixel detector, which exploits wafer-bonded silicon on insulator (SOI) substrates for integration of the readout electronics with the pixel detector, is presented. The main concepts of the proposed monolithic sensor and the preliminary tests results with ionising radiation sources are addressed. Silicon on insulator is an alternative solution for a monolithic active pixel detector, which allows integrating a fully depleted sensor and front-end electronics active layers into one silicon wafer. The main idea of the sensor relies on the use of both monolithic silicon layers (device and support layers) of the SOI substrate for fabrication of pixel detector diodes and readout electronics. Such detectors can find wide range of applications, not only in particle physics but also in medicine, space science and many other disciplines. The sensor structure and the readout configuration have been developed and the measurements of a dedicated test structure have validated the new technology of the SOI detector. Small SOI sensor matrices with 8 by 8 channels have been recently produced and tested.

A simple method for characterization of MOSFET serial resistance asymmetry

A method for a direct extraction of individual serial resistances of MOSFET source/drain electrodes is presented. It is based on the device I-V characteristics in a saturation range measured for two device configurations inverted with respect to source and drain electrodes. A threshold voltage necessary for the saturation range modeling is determined from the non-saturation range I-V characteristics. Based on the measurement data determined for the SOI MOSFETs fabricated in ITE the proposed method has been compared with other techniques.

A simple multi-purpose method for compact model evaluation

A simple method for data analysis in semiconductor device characterization and compact modeling is proposed. The method allows for a direct comparison of data originating from different sources, e.g. from measurement and simulation. The comparison is carried out via forming a direct correlation between the device characteristics under consideration, e.g. between the currents of the real device and the corresponding model. The resulting cloud of points together with the numerical indices characterizing their linear regression give information about the quality of fitting. The method is multipurpose and may be used for different tasks like scaling or variability effect investigation.

SOI-Based Microsensors

A silicon-on-insulator (SOI) technology has become a key tool for manufacturing of microsensors. A number of the SOI-based microsensors have been presented in the chapter. The developments are related mostly to non-electrical sensors. Most of them have been developed at Instytut Technologii Elektronowej (ITE) Warsaw, in collaboration with numerous partners. The chapter is divided into two main sections describing the technology and device issues. First, ITE expertise in the area of SOI technologies is described. The SOI CMOS processes based on wafers with a thick and thin device layers are presented. The CMOS technology has become an origin for a PaDEOx technique developed for narrow (order of 100 nm width) line fabrication on the silicon wafers, which allows for development of nanowire-based devices (e.g. multi-gate MOSFETs). The second branch of the SOI technologies, being under development in ITE, includes micromachining techniques. Based on the SOI technologies, a number of devices have been developed with the ITE participation. The following solutions have been presented: monolithic pixel detectors of ionizing radiation, sub-THz radiation detectors based on a concept of radiation-induced plasmon oscillations in the MOSFET channels, smart antennas with a reconfigurable aperture. Next, devices fabricated based on micromachining techniques have been mentioned, e.g. microactuators and probes for scanning thermal microscopy. Finally, development of SOI-based biochemical sensors for small volume sample testing is more widely described. These devices have been manufactured based on the PaDEOx technique and have been applied for analysis of hydrogen an metal ions in water solutions.

Design, Fabrication and Characterization of SOI Pixel Detectors of Ionizing Radiation

Development of a novel monolithic active pixel image sensor based on SOI technology is presented. Active pixel test matrices have been recently manufactured and are under extensive examination. This paper describes the concept of the device and shows the most recent results.