Marc Finot

Determination of thin-film stresses on round substrates

Thin films deposited on wafers show, in some cases, large variations in stress. The local curvature is often used in the Stoney equation [G. G. Stoney, Proc. R. Soc. London, Ser. A 82, 172 (1909)] to calculate the local stress. This practice leads to false stress results. A general method for the calculation of the film stress, for films with isotropic stress, is presented here. The stress is calculated from both the local and overall shape of the substrate. Simple examples of isotropic stress were simulated and the substrate deformation calculated. The film stress was calculated back from the substrate shape with good agreement with the initial stress distribution. The substrate shape under films with centrosymmetric stress distribution can be analytically calculated. The current method successfully calculates the stress distribution from the substrate shape. Some guidelines for the deviation of the calculated stress from that of Stoney’s are given. Finally, the case of nonisotropic stressed film cannot ...

Automated opto-electronic packaging for 10 Gb/s transponders

Integrated transponders are quickly displacing discrete module implementation in many 10 Gb/s line card designs. The emergence of the 10 Gigabit Ethernet (10 GbE) standard had placed higher demands on manufacturing scalability to meet the volume requirements of this application. To meet these challenges, we have developed a novel automated manufacturing implementation of small form factor, high performance, and highly integrated uncooled optics. We describe the design and automated manufacturing of such modules, present their performance, and show how they enable the implementation of new miniature, low cost 10 Gb/s transponders.

Wavelength Filter with Integrated Thermal Control used as an Intracavity DWDM Laser Tuning Element

A thermally tuned silicon wavelength filter with integrated thermal isolation and control elements is described. Placed within the laser cavity of an external cavity semiconductor laser, this filter enables full-band tuning that meets all requirements for deployment in DWDM telecommunication systems

Thermally tuned external cavity laser with micromachined silicon etalons: design, process and reliability

A broadly tunable external cavity laser, employing thermally tuned etalons and laser-welding manufacturing is presented. The design of the tunable laser module is based on the quasi-planar manufacturing technology that is used for multiple other Intel products such as 10 Gb/s transponders and transceivers for Sonet and Ethernet applications. The laser cavity is defined at the output end by the gain chip facet and by an external mirror at the other end. An intracavity filter comprises two micromachined thermally-tuned silicon etalons manufactured to have slightly different free spectral ranges. The output optics of the external cavity laser are similar to those found in single-channel lasers. The density of optical components and the alignment precision required presented challenges for the development of scalable component placement processes and packaging. However, excellent performance has been obtained as evidenced by short-term stability under thermal and mechanical stress tests and long-term stability under accelerated stress tests.

Automated opto-electronic packaging for 10 Gb/s applications

We demonstrate a new ceramic-based quasi-planar optoelectronic packaging technology specifically designed for high-speed performance and automated manufacturing. Its application to the development of miniature, low cost 10 Gb/s transponders is reviewed.