{"id":29315,"date":"2004-02-01T00:10:28","date_gmt":"2004-02-01T00:10:28","guid":{"rendered":"https:\/\/silvaco.com\/uncategorized\/simulation-of-silica-microlenslet-formation-by-etch-and-reflow-using-elite-and-ssuprem4\/"},"modified":"2021-07-08T18:31:21","modified_gmt":"2021-07-09T01:31:21","slug":"simulation-of-silica-microlenslet-formation-by-etch-and-reflow-using-elite-and-ssuprem4","status":"publish","type":"post","link":"https:\/\/silvaco.com\/ja\/simulation-standard\/simulation-of-silica-microlenslet-formation-by-etch-and-reflow-using-elite-and-ssuprem4\/","title":{"rendered":"Simulation of Silica Microlenslet Formation by Etch and Reflow Using Elite and SSuprem4"},"content":{"rendered":"
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Simulation of Silica Microlenslet Formation by Etch and Reflow Using\u00a0Elite<\/em>\u00a0and\u00a0SSuprem4<\/em><\/strong><\/h1>\n

Introduction<\/h3>\n

In response to high demand, device designers are developing silica microlenslets that offer efficient coupling between optical fiber bundles and arrays of photodetectors, LEDs, or VCSELs. Microlenslet design involves precise control of the surface curvature in order to place the focus in the optimal region.<\/p>\n

ATHENA<\/strong><\/em>, Silvaco\u2019s physically based process simulation software, helps device designers to simulate the entire fabrication sequence and to determine the effectiveness of the design through ray tracing and device simulation. The software also checks prospective designs and helps calibrate relevant material parameters with lenslet profiles that are easily imported from microscopy or raw calculations.<\/p>\n

Device Operation<\/p>\n

As an example, let\u2019s take a single photodetector with a surface-integrated silica microlenslet that forms a compact device with focusing and photon detection capabilities. The microlenslet collects the light signal from the optical fiber and focuses the light into the absorption region of the detector. The signal strength is the strongest at the focal point and so is the photogeneration rate. Consequently, the coupling efficiency and the sensitivity of the device are improved.<\/p>\n

Device Fabrication Processes (SSuprem4<\/em>\u00a0and\u00a0Elite<\/em>\u00a0required)<\/p>\n

The simulated formation of this detector-lenslet device begins with the process simulation of the detector, including metal electrodes and a protective glass covering. The formation of the microlenslet in this example involves depositions, reactive ion etching, and a low-temperature reflow that has no effect on the underlying detector.<\/p>\n

The starting point for lenslet formation is on top of the photodetector array after the overglass or planarization layer. At this point, a layer of silica that features the desired refractive index and appropriate thickness is laid down. A photoresist layer of the necessary thickness, viscosity, and surface tension properties covers the silica. The outline of the microlenslet is defined by exposing and removing the unwanted portion of the photoresist layer defines<\/p>\n<\/div><\/section><\/div>

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