The definition of Cleaning in the semiconductor processing is more or less: to get rid of dirt, contaminants, or any extraneous matter by means of wet (chemical) processing in a good, reproducible and constant way. ‘Good’ means it does not influence the result of the final device or interfere with the property of the subsequent layer.
And because the architectures are getting smaller all the time Cleaning in the IC-technology becomes more and more important. Therefore being able to remove
contaminants in a structured and reproducible way without damaging any possible structures
already present is a strong upcoming issue within TFF also!
In cleanroom WAG, besides the usual tanks, two systems are available for automatically wet cleaning of substrates:
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SSEC Trilennium: a single wafer cleaning tool
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UP Wet Bench: a batch processing cleaning street
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SSEC Trilennium Cleaning Tool The SSEC Trilennium cleaning tool is a highly flexible apparatus. This flexibility is gained due to the capability of handling various substrate sizes together with 7(!) different cleaning options, which can be utilized in each required sequence. With respect to the substrate sizes this means 100mm, 150mm and 200mm round substrates as well as 4”, 5”, 6” and 7” square substrates. By fabricating a new substrate holder it is also possible to handle any rectangular substrate that consists of a combination of the mentioned square sizes. The system is a single-substrate cleaning tool equipped with four dispense arms, each with its own cleaning option: Arm 1: Pre-mixed 1%HF solution Arm 2: Point-of-Use mixed ‘Piranha’. Arm 3: Quartz nozzle equipped with an enclosed 1,5 MHz megasonic transducer for dispensing pre-mixed APM solution, 1%NH4OH-solution or DI water. Arm 4: High-pressure (max. 3000 psi) nozzle with pre-mixed 1%NH4OH solution. Besides these four arms a wall-dispense with hot (85ºC) and ambient DI for rinsing purposes, is mounted also. These options are all fully, and independently from each other programmable. For more information see
DTS Report nr 04-010. |
Universal Plastics Wet Bench
The UP Wet Bench is a batch processing tool capable of handling practically any kind of substrate. The only restriction towards the substrate size and shape is that a cassette has to be available. Cassettes for non-standard substrate sizes can be tailor made, as long as the outer dimensions of the cassette are standard. The system consists of 4 processing tanks, a YieldUP
2000® rinser/dryer and a handler. The solution of each of the 4 processing tanks is constantly filtered through a 1 µm filter by means of a closed, circular pump-system. Furthermore, the separate
solutions can be kept on a constant temperature via indirect water heating (max T
= 60ºC) through an external heater/cooler system.
The available cleaning solutions in the UP Wet Bench are:
Tank 1: 96% H2SO4 (‘dirty’)
Tank 2: 96% H2SO4 (‘clean’)
Tank 3: Deconex 12NS (pH 11,7). This is a high performance cleaning solution for glass, wafers and optical or electronic components. This tank is also equipped with a megasonic transducer for a more thorough particle removal.
Tank 4: Not filled yet. Right now this is a spare tank, which can be filled with a later to be decided cleaning or etching solution.
The integrated rinser/dryer is stand-alone system featuring FSI’s STG® Technology (Surface Tension Gradient). This technology uses the Marangoni effect to dry
substrates without leaving behind watermarks. Within the recipe editor the 4 tanks and the rinser/dryer are with respect to temperature, time and sequence, independently from each other programmable. This provides the opportunity to use different recipes for cleaning different contaminations and/or substrates.