Semiconductor Devices

Bridging the Gap from Material to Application

Technology stands above all for research and development in the field of electronic devices for CMOS as well as for power applications. Based on comprehensive cleanroom facilities, silicon, as well as silicon-carbide processing, forms the backbone of the technology.

The Semiconductor Devices Department is your contact for the design, realization and characterization of single process steps and devices up to prototypes manufactured in our continuous silicon CMOS and silicon carbide process line in an industry-compatible environment.

Examples for current activities are sensor devices, advanced integrated power devices on SiC, or high-temperature electronics. The heterogeneous integration of various technologies is currently acquiring more and more importance.

• Device Design
• Process Development
• Processing and Prototype Fabrication (π-Fab)
• Characterization and Analytical Methods

In the field of ‘Devices’ we develop innovative device solutions with a strong focus on power electronics. This includes novel device concepts both on semiconducting materials like silicon and silicon carbide and on related materials providing a “technology-push” towards new and more powerful applications.

We cover activities from monolithic integration of electron devices, development and integration of passives, including new dielectric materials and especially capacitors, as well as new power semiconductor devices. Our power electronic devices and circuits are implemented in power grid applications, in automotive electronics such as electric mobility, and furthermore in the fields of biotechnology and medicine. Additionally – and to meet rising requirements – we pay special attention to research and development on high temperature electronics and sensors suitable for particularly demanding environments.

Power Devices: Customer-driven development and manufacturing of power semiconductor devices on silicon and silicon carbide

High Temperature Electronics & Sensoring: Development and operation of sensors, signal processing and actuators operable up to 600° C.

Passives: Development of novel capacitors with regards to higher integration density, higher temperature, and higher voltage stability as well as simplified mounting and assembly

Thin-Film Devices and Systems: Thin-film transistors and sensors for direct application in industrial, automotive, energy and consumer electronics.

Key to keep up with today‘s requirements of digitalisation and the ongoing transition to renewable energy sources are novel semiconductor device concepts. To meet the market needs and the customers expectations, we offer custom-tailored process solutions in order to realize innovative, power- and cost-efficient devices, based on silicon-carbide. With our know-how and technology we focus on proof-of-concept prototyping and proof of manufacturability for advanced fabrication processes. Having proven processes in combination with an accordingly aligned and already proven process flow reduces the entrance barrier for introducing such a prototype into a volume fabrication. In such case, IISB offers also a small volume fabrication to close the gap between prototype development and high volume fabrication.

• Wafer thinning for 4H-SiC power MPS-diodes: total thickness reduction from 370 µm to 90 µm, (65 µm substrate thickness), resulting in on-resistance reduction of 30 % in Schottky and 60 % in conductivity modulation state, respectively, while maintaining its initial blocking capabilites.
• Trench formation for 4H-SiC TrenchMOS fabrication: on-resistance reduction due to vertical channel formation along the trench sidewall, resulting in a reduced cell-pitch with no JFET region compared to the planar MOSFET. As a consequece, higher cell integration density enables to reduce and save chip area and ultimately chip costs, respectively.

As part of IISB‘s ‚Semiconductor Devices‘ we operate our stand-alone brand π-Fab – a prototyping service which comprises a continuous silicon CMOS and silicon carbide process line in an industry-compatible environment. π-Fab is the result of three decades of experience in microelectronics research and development, in which we extended our activities to industry-oriented low-volume prototype fabrication of custom-tailored electron devices, with a focus on power devices, CMOS devices, passives, sensors, and MEMS. The unique characteristic of π-Fab is a high flexibility in wafer material and size. Silicon wafers with diameters of 150 mm and 200 mm are handled by default, further diameters on request. The process line is based on a 0.8 μm Si-CMOS technology. To keep flexibility high an advanced contamination control is available.

Special attention has been given to silicon carbide (SiC) device processing on 100 mm and 150 mm wafers. In order to realize all dedicated SiC process steps, such as epitaxy, ICP dry trench etching, growth of silicon dioxide, implantation at elevated temperatures, implant activation annealing, or ohmic contact alloying, we provide additional equipment. Furthermore, π-Fab is designed as a platform where equipment assessment and optimization, or manufacturing control issues for customers can be covered. It thus also forms the basis for IISB’s SiC-Services, which cover the whole value chain, from material to devices, SiC modules development and assembly up to implementation of SiC mechatronic systems.

Characterization

Performance and reliability characterization through measurement of device performance, statistical device reliability predictions considering individual failure mechanisms as well as process evaluation based on yield analysis. Electrical contamination analysis such as carrier lifetime measurements or DLTS for process control or material characterization are being offered in addition.

Contamination Control

In the field of contamination control we are developing or adapting analytical methods and sample preparation methods for the customer-specific cases. More Moore as well as More-than-Moore applications are being addressed. Our focus is the developement of advanced contamination control methods for yield enhancement. Solutions for the characterization of wafers, processes, media, materials, and equipment concerning their contamination behavior, for determining contamination sources, and for certifying cleanroom suitability are being developed together with partners.

Preparation and analysis of nanostructures with the Focused Ion Beam (FIB)

With our dual-beam systems consisting of a scanning electron microscope (SEM) and a focused ion beam (FIB), we process and image any materials simultaneously and with nanometer precision. This allows us to analyze defects in assembled systems, visualize doping and damage processes in implanted devices, analyze cross-sections in a layered system or perform local process control on wafers. Our decade-long experience with a wide variety of materials opens up a long list of preparation and analysis options from semiconductor materials to polymers, glasses, diamonds, bones, metals, crystals, ceramics, ...