Two different field solver tools have been developed in order to facilitate fast thermal and electro-static simulation of microsystem elements. The /spl mu/S-THERMANAL program is capable of the fast steady-state and dynamic simulation of suspended multilayered microsystem structures. The 2D-SUNRED program is the first version of a general field solver based an an original method, the successive node reduction. SUNRED offers a very fast and accurate substitute of FEM programs for the solution of the Poisson equation. Steady-state and dynamic simulation examples demonstrate the usability of the novel tool.

Besides foundry facilities, Computer-Aided Design (CAD) tools are also required to move microsystems from research prototypes to an industrial market. Currently available CAD tools need extensions before they can be used for the automated design of micromachined devices. This paper presents a low cost access to microsystem technology (MST), applied by the CMP service, and based on the use of existing microelectronics production lines, with additional post-processing for microsystem specific 2D and 3D structures, and a global CAD approach for the design and simulation of microsystems applied to currently available commercial CAD tools, e.g. Mentor Framework, in order t o ensure a continuous flow from the design to the manufacturing.

To solve the problem of fast thermal and electrostatic simulation of microsystem elements two different field solver tools have been developed at TUB. The /spl mu/S-THERMANAL program is capable for the fast steady state and dynamic simulation of suspended multilayered microsystem structures, while the 2D-SUNRED program is the first version of a general field solver program, based on an original method, successive network reduction. This program offers a very fast and accurate substitute for FEM programs for the solution of the Poisson equation, e.g. solving a 32000 grid problem in about 6 minutes on a 586 PC. Application examples show the usability of the tools.

The continuously increasing power densities in integrated circuits necessitated the introduction of DfTT (Design for Thermal Testability) design methodology to prevent overheating effects. Newly developed CMOS temperature sensors enable the application of DfTT principle in safety-critical circuits. Parameters and operation principles of the low-power small-area temperature sensor family are presented in details in the paper, followed by the discussion of placement and testing strategies.

The paper presents appropriate sensors for the realization of the design principle of design for thermal testability (DfTT). After a short overview of the available CMOS temperature sensors, a new family of temperature sensors will be presented, developed by the authors especially for the purpose of thermal monitoring of VLSI chips. These sensors are characterized by the very low silicon area of about 0.003-0.02 mm/sup 2/ and the low power consumption (200 /spl mu/W). The accuracy is in the order of 1/spl deg/C. Using the frequency-output versions an easy interfacing of digital test circuitry is assured. They can be very easily incorporated into the usual test circuitry, via the boundary-scan architecture. The paper presents measured results obtained by the experimental circuits. The facilities provided by the sensor connected to the boundary-scan test circuitry are also demonstrated experimentally.

Due to severe thermal problems of today's VLSI integrated circuits the need for reliable and quick thermal, electro-thermal and logi-thermal simulation tools is increasing, In this paper, we discuss the latest advances in the SISSI package (simulator for integrated structures by simultaneous iteration) which is a tool developed originally for analog VLSI design. The improvements include electro-thermal ac and transient simulation and the consideration of the thermal voltage of Si-Al contacts. Furthermore, we introduce a new module of SISSI, LOGITHERM, which is aimed at the self-consistent logic and thermal simulation of large digital VLSI designs. The features of our simulator package are highlighted by simulation examples that are compared in most cases with measurement results.

On-line temperature monitoring of safety-critical ICs and systems becomes more and more crucial because of downsizing of integrated circuits and of increased density due to advanced packaging. To prevent erroneous operation, temperature sensors should be placed on the critical spots, the outputs of which should be read by means of boundary scanned architectures or modified boundary scanned architectures in case of on-line monitoring.