Kenneth J. Giewont

X ray fills the gap

X-ray lithography has been used in mix and match mode with optical steppers to build test circuits in support of DRAM and Logic development at IBMs Advanced Semiconductor Technology Center, ASTC. Prior to building the test devices, hundreds of wafers were exposed using x-ray lithography to define the etch processes for critical levels and to help separate optical lithography, resist and etching effects. The demand for this type of support required IBMs Advanced Lithography Facility (ALF) to focus on a set of pilot line issues not previously faced by this emerging lithography. The challenges and solutions which resulted are discussed. This paper examines the requirements for the introduction of x-ray into pilot line use based on ALFs most recent experience and performance.

Top-side electroluminescence: a failure analysis technique to view electroluminescence along a laser channel

Electroluminescence imaging along the optical channel of a laser diode can show non-radiative defects or non-uniform emission in the channel which may be contributing to failure. This imaging technique is easily done on specially prepared test sites or on lasers that have not been diced and packaged. Once the laser diode is packaged (typically in a TO type package) it is difficult to utilize this technique due to the difficulty in successfully exposing the optical channel for inspection. This paper describes a practical technique to perform optical channel electroluminescence imaging of packaged laser diodes. It has been successfully applied to 780nm, 800nm, and 1300nm laser diodes. The information obtained can be used to improve reliability and/or life of the product analyzed. This paper will highlight details of the technique along with illustrations of typical results. Applications to failure analysis will also be discussed.