Paper
3 September 1999 New optical sensor for real-time in-situ end point monitoring during dry etching of III-V ternary multistack layers
Kevin J. Liddane, Ramdane Benferhat, Jewon Lee, Russell J. Westerman, David J. Johnson, John Donohue, Jay N. Sasserath, Stephen J. Pearton
Author Affiliations +
Abstract
There has been a great demand for improved end point detection techniques for advanced etching of III-V ternary multi stack layers. Current etch rate and end point monitoring techniques are based on three methods. The first is to use timed or a blind etch as it is known, this offers no monitoring of the etch process. The second is to use optical emission spectroscopy (OES) which is a secondary measurement of the process and requires a large open area, fast etch rate, and a detectable emission line from the etch products. The third is laser interferometry, a primary measurement, based on light interference of reflected beams from several layers in the stack. Up to now the use of commercially available interferometric techniques has not permitted the measurement of etch rates and end point the etch processes due to the absorption of the wavelengths of light available in current process control systems. A new in-situ end point system utilizing a 905 nm laser interferometer will be described that allows the ability to follow dry etching of III-V ternary multi stack layers. End point detection techniques on various AlxGa1-xAs layers on GaAs with varying compositions (i.e. X equals 0.3 - 0.92) and different types (n- or p- AlGaAs) are examined.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kevin J. Liddane, Ramdane Benferhat, Jewon Lee, Russell J. Westerman, David J. Johnson, John Donohue, Jay N. Sasserath, and Stephen J. Pearton "New optical sensor for real-time in-situ end point monitoring during dry etching of III-V ternary multistack layers", Proc. SPIE 3882, Process, Equipment, and Materials Control in Integrated Circuit Manufacturing V, (3 September 1999); https://doi.org/10.1117/12.361321
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Cited by 1 scholarly publication and 1 patent.
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KEYWORDS
Etching

Interferometry

Gallium arsenide

Cameras

Semiconducting wafers

Process control

Control systems

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