Specific Process Knowledge/Etch/DRIE-Pegasus: Difference between revisions
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**''then'' as the bottom of the structures are opened the etch of silicon itself starts. | **''then'' as the bottom of the structures are opened the etch of silicon itself starts. | ||
Here, it is clear that one can distinguish two phases of the etch cycle; one where the ion bombardment removes the polymer and one where the actual etching takes place. Considering what process conditions are favorable we realize that | Here, it is clear that one can distinguish two phases of the etch cycle; one where the ion bombardment removes the polymer and one where the actual etching takes place. Considering what process conditions are favorable we realize that | ||
*the ion bombardment requires a low pressure in order for the ions to have a long mean free path and hence good directionality. | *the ion bombardment requires a low pressure in order for the ions to have a long mean free path and hence good directionality. Also, a high platen power is required to drive the ion bombardment. | ||
*a higher pressure during the etch increases the density of reactive species and hence the etch rate. Since a high platen power is no longer necessary to drive the ion bombardement, lowering it will reduce the impact on the masking material thus improving the selectivity. | *a higher pressure during the etch increases the density of reactive species and hence the etch rate. Since a high platen power is no longer necessary to drive the ion bombardement, lowering it will reduce the impact on the masking material thus improving the selectivity. | ||
The hardware improvements on the DRIE-Pegasus include | The hardware improvements on the DRIE-Pegasus include | ||
*Fast response MFC's mounted on top of the process chamber itself to shorten the gas line | *Fast response digtal MFC's mounted on top of the process chamber itself to shorten the gas line | ||
*Fast APC valve | *Fast APC valve | ||
* | *Fast RF power supply | ||
===[[Advanced_Silicon_Etcher_-_Pegasus|Details on DRIE-Pegasus]]=== | ===[[Advanced_Silicon_Etcher_-_Pegasus|Details on DRIE-Pegasus]]=== | ||