Bruno Miller

Characterization of silicon wafer bonding for Power MEMS applications

This paper reports the investigation of low-temperature silicon wafer fusion bonding for MEMS applications. A bonding process utilizing annealing temperatures between 400 and 1100 °C was characterized. The silicon–silicon bonded interface was analyzed by infrared transmission (IT) and transmission electron microscopy (TEM) and the bond toughness was quantified by a four-point bending–delamination technique.

Comparing Urban and Rural Telecenters Costs

If deployed in both urban and rural areas, telecenters can decrease the gap in social services and economic opportunities that often exist between the two. However, establishing and operating rural telecenters is perceived to be more costly than urban ones. This paper presents a cost comparison of establishing urban and rural telecenter in Costa Rica. It shows that telecenter operations in rural areas disconnected from the power and telecommunication grids may not be significantly more expensive than those of an urban telecenter. Utilization of stand‐alone communication and power systems, combined with low‐power equipment can bring rural operating costs within range of those of a typical urban telecenter. The analysis is based on the Little Intelligent Communities (LINCOS) telecenter project, an initiative of the Foundation for Sustainable Development of Costa Rica.

Characterization of Silicon Fusion Bonds Using a Four-Point Bend Specimen

The increased number of MEMS devices that are fabricated by bonding two or more bulk micromachined silicon wafers has highlighted the need to produce reliable silicon fusion bonds. The current study focuses on employing a four-point bend delamination specimen to measure silicon fusion bond strength as a function of processing conditions. The specimen, which is composed of two bonded layers and an initial notch, permits the measurement of a mixed-mode critical strain energy rate, G C , at the interface. This specimen geometry is advantageous because it does not require measurement of crack length to calculate the strain energy release rate and is insensitive to damage near the specimen edges. The fact that the interface is loaded under mixed-mode conditions presents difficulties in achieving stable crack propagation in well bonded specimens. Attempts were made to eliminate this problem by reducing the effective bond toughness by etching shallow grooves in the wafer surfaces to reduce the bonded area. Testing revealed that while this approach reduced the effective toughness of the interface, it did not prevent crack deflection in well bonded samples. Despite the limitations of the specimen, data was obtained for silicon fusion bonds fabricated under various annealing and contacting conditions. Test results indicate an increase in bond toughness with annealing temperature and time. The data also suggests that the contacting pressure and duration have little effect on bond quality. The specimen, while limited to characterizing bonds with lower toughness, proved straightforward to fabricate and test.

Application of Real Options to Evaluate the Development Process of New Aircraft Models

Investment decisions in the development and production of new aircraft models is difficult because of the technical and market uncertainties associated with such a complex process. The accompanying risks can be mitigated through a flexible approach that incorporates several decision points at different stages of the process. Therefore, as the project evolves, management will be able to diagnose its progress, compare it to previous expectations, and decide to continue or not. In this paper, we present a methodology to evaluate flexible business strategies that is based on real options analysis (ROA) and Monte Carlo simulation. This methodology takes into account the flexibility that managers have to affect the success of any given project and, therefore, it provides a better estimate of project value. Numerical results are given for a representative process based on actual aircraft manufacturers data.

Investments in Rural Air Transportation Networks in Developing Countries

Rural airfields provide vital access to many remote regions of the world, thus enabling their socioeconomic development. While these facilities are usually very simple, their construction and maintenance can be very difficult. Thus, governments must balance the need to provide access with the cost of providing access. In this paper, we present a quantitative methodology for evaluating investment decisions in rural air transportation networks. The intended purpose of the methodology is to provide policymakers with enough understanding so that they can develop strategies that meet the accessibility needs of remote locations while making the best use of available resources. The first step in the methodology is to determine the importance of air links to the different points in the network. Next, the existing and desired infrastructure are evaluated in terms of their ability to support the expected traffic. These evaluations are followed by a gap analysis to determine the infrastructure deficit and provide the basis for the formulation of different investment strategies. In this paper we consider the case of Costa Rica and provide useful insights for policymakers interested in supporting rural air transportation networks.

Low temperature silicon wafer bonding for MEMS applications

This paper reports the investigation of low-temperature silicon wafer fusion bonding for MEMS applications. A bonding process utilizing annealing temperatures between 400/spl deg/C and 1100/spl deg/C was characterized. The silicon-silicon bonded interface was analyzed by Infrared Transmission (IT) and Transmission Electron Microscopy (TEM) and the bond strength was quantified by a four-point bending-delamination technique.

Using Real Options to Determine the Optimal Investment Schedule

Investment Schedule Antonio M. Abad and John Paul Clarkey Massachusetts Institute of Technology, Cambridge, MA, 02139, USA Bruno Millerz Massachusetts Institute of Technology, Cambridge, MA, 02139, USA Modernization of the National Airspace System (NAS) has in large part been the result of infrastructure investments by the Federal Aviation Administration (FAA). These investments have typically required large capital expenditures over long periods of time. Given current budget constraints and the uncertain environment characteristic of air transportation, the FAA is increasingly pressed to be more selective in terms of the investments that they make. As part of this e ort they must ensure that they have a realistic valuation for each product. In this paper we present an analytical model based on real-options theory that describes the relationship between investment level and performance in the Product Development (PD) process for a single product. The model uses a Monte Carlo-based System Dynamics (SD) framework to simulate the di usion process in environments of arbitrary complexity. Unlike previous formulations, no assumptions need to be made about the di usion process. Estimation Theory is used to model how management can leverage past data to lter out measurement noise and mitigate the impact of making wrong decisions during the development process. Thus, this paper provides both a valuation methodology that captures the exibility and learning inherent in the PD processes as well as a control law that can guide management dynamically in developing the optimum development strategy. Nomenclature g(ti) Observed variance of present program value estimate error at design review i i Design review/time index j Continuous program value index m(ti) Measured present program value at design review i p(ti) Estimated variance of present program value estimation error at design review i V (ti) Actual present program value at design review i V (ti) Estimated present program value at design review i v1(ti)Decision threshold between abandonment and improvement at design review i v2(ti)Decision threshold between improvement and continuing at design review i V Cumulative program value at program commencement