Specific Process Knowledge/Etch/Etching of Silicon Nitride: Difference between revisions
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==Comparison of wet Silicon Nitride etch and RIE etch for etching of Silicon Nitride== | ==Comparison of wet Silicon Nitride etch and RIE etch for etching of Silicon Nitride== | ||
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! Wet Silicon Nitride etch | ! Wet Silicon Nitride etch | ||
! Buffered HF (BHF) | |||
! RIE | ! RIE | ||
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| | | General description | ||
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*Isotropic etch | *Isotropic etch | ||
*Well suited for removing all nitride on a wafer surface (nitride strip) without a mask. High selectivity Si3N4/Si (>100) and Si3N4/SiO2 (>20) @ 180 C. | *Well suited for removing all nitride on a wafer surface (nitride strip) without a mask. High selectivity Si3N4/Si (>100) and Si3N4/SiO2 (>20) @ 180 C. | ||
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*Isotropic etch | |||
*Well suited for removing all PECVD nitride on a wafer surface (nitride strip) without a mask. Etches LPCVD nitride very slowly | |||
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*Anisotropic etch: vertical sidewalls | *Anisotropic etch: vertical sidewalls | ||
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*Silicon Oxide | *Silicon Oxide | ||
*PolySilicon | *PolySilicon | ||
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*Photoresist | |||
*PolySilicon | |||
*Blue film | |||
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*Photoresist | *Photoresist | ||
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*Stoichiometric Silicon Nitride @ 180 <sup>o</sup>C: ~84 Å/min | *Stoichiometric Silicon Nitride @ 180 <sup>o</sup>C: ~84 Å/min | ||
*Stoichiometric Silicon Nitride @ 160 <sup>o</sup>C: ~60 Å/min | *Stoichiometric Silicon Nitride @ 160 <sup>o</sup>C: ~60 Å/min | ||
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*PECVD nitride: ~400-1000 Å/min | |||
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*Typically 40-50 nm/min can be increased or decreased by using other recipe parameters. | *Typically 40-50 nm/min can be increased or decreased by using other recipe parameters. | ||
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| | |Batch size | ||
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*1-25 wafers at a time | |||
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*25 wafers at a time | *1-25 wafers at a time | ||
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*1 wafer at a time | *1 wafer at a time | ||
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|Size of substrate | |Size of substrate | ||
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*4" wafers | |||
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*4" wafers | *4" wafers | ||
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*4" wafers or smaller pieces | *4" wafers or smaller pieces | ||
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|Allowed materials | |||
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*Silicon | |||
*Silicon Oxide | |||
*Silicon Nitride | |||
*Silicon Oxynitride | |||
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*Silicon | |||
*Silicon Oxide | |||
*Silicon Nitride | |||
*Silicon Oxynitride | |||
*Photoresist | |||
*Blue film | |||
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|} | |} | ||