Memorias de investigación
Communications at congresses:
UV laser-induced high resolution cleaving of Si wafers for micro-nano devices characterization

Research Areas
  • Fluid mechanics,
  • Electronics engineering,
  • Naval engineering,
  • Magnetic materials

Silicon based mass production technology at micro-nano scale is increasing the number of devices every year. This miniaturisation and integration is increasing the functionality of micro-nano devices rapidly for a broad field of applications such as micro-nano systems, MEMS, MOEMS, lab-on-a-chip, sensing devices, among others. In this term, high resolution wafer dicing and cleaving is becoming a significant feature in order to control both: the micronano fabrication processes and the devices functionality characterization. In the manufacture of such devices, the initial fabrication steps are normally implemented on a Si wafer that will contain a large number of devices. After an initial set of processing steps at wafer level, many times the wafers have to be cleaved to analyse the vertical facets in order to control the fabrication processes or, in the case of photonic devices, input and output waveguides have to be accessible to evaluate the devices optical response, or for the waveguides-fibers coupling implementation. However, although wafer dicing and polishing is a reliable process for this purpose, it is time consuming and a significant know-how is needed to be implemented at micro-nano scale. Laser micromachining research and technology systems have been widely applied in the last twenty years in micronano fabrication processes development. In this work, a high resolution method is presented reaching wafer submicron domains by using a Nd:YVO4 laser (Spectra Physics HIPPO) emitting pulsed UV radiation at 355 nm in ns pulse regime and a high resolution positioning system for Si wafer cleaving without human manual intervention. The laser has been used for making grooved marks placed at the desired locations and direction where cleaves have to be initiated with a micrometric resolution. Because of this, a tensile strain is applied to the material during the laser cutting process initiating the cleavage crack formation and propagation in the same direction of the laser groove mark through the bulk of the material. The grooves formation provide a well-controlled mechanism for a clean crack formation through the material to reach sub-micro domains in micro-nano structures fabricated over Si wafer for their analysis. The results obtained on a fully automatized laser micromachining workstation based on the main concept of flexibility are presented in order to offer a solution to easily control the cleaving process to reach sub-micron size locations for both: devices characterization and micro-fabrication processes control.
9th International Symposium on Laser Precision Microfabrication LPM-2008
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Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Ingeniería y Aplicaciones del Láser
  • Centro o Instituto I+D+i: Centro Laser
  • Departamento: Física Aplicada a la Ingeniería Industrial