کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1671528 | 1008918 | 2009 | 6 صفحه PDF | دانلود رایگان |
We studied the etch-depth control of 980 nm intracavity contacted vertical-cavity surface-emitting laser (VCSEL) structures with GaAs/AlGaAs distributed Bragg reflectors by in-situ laser reflectometry and reflectivity modeling in SiCl4/Ar inductively coupled plasmas. Highly accurate etch-depth control can be achieved by counting the number of oscillation peaks in the experimental reflectance signal through the fitting of the reflectivity data calculated theoretically using a transfer matrix method. The fits provide a very good agreement, allowing us to distinguish individual layers precisely and stop the etching at a desired depth. After confirmation of the validity of in-situ dry etch monitoring, this technique was employed in the fabrication of microlens-integrated intracavity contacted VCSELs including composition-graded digital alloy AlGaAs for high precision control of the etch depth in intracavity region. The etch-depth difference between calculated and experimental results was kept below 20 nm, indicating a good etch performance. The spatial uniformity of ~ 5% was obtained over 1 × 1 cm2 sample size.
Journal: Thin Solid Films - Volume 517, Issue 19, 3 August 2009, Pages 5773–5778