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| Wafers with metals or other materials, not allowed in the dedicated oxide etch baths, can be etched in the PP-bath positioned in the fume hood in cleanroom 2 or in a '''plastic''' beaker. | | Wafers with metals or other materials, not allowed in the dedicated oxide etch baths, can be etched in the PP-bath positioned in the fume hood in cleanroom 2 or in a '''plastic''' beaker. |
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| ===Silicon oxide etch data===
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| {| border="2" cellspacing="0" align="left" cellpadding="5"
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| !
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| ! BHF
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| ! 5% HF
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| ! 40 % HF
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| ! SIO
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| |-valign="top"
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| |'''General description'''
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| Etching of silicon oxide with a stable etch rate
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| Mainly for removing native oxide
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| Mainly for etching deep into borofloat or quartz wafers
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| Etching of silicon oxide - especially for etching small holes
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| |-valign="top"
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| |'''Link to safety APV and KBA'''
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| |[http://www.labmanager.danchip.dtu.dk/d4Show.php?id=1897&mach=64 see APV here]
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| [http://kemibrug.dk/KBA/CAS/106534/?show_KBA=1&portaldesign=1 see KBA here]
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| |[http://www.labmanager.danchip.dtu.dk/d4Show.php?id=1897&mach=64 see APV here]
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| [http://kemibrug.dk/KBA/CAS/106534/?show_KBA=1&portaldesign=1 see KBA here]
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| |[http://www.labmanager.danchip.dtu.dk/d4Show.php?id=2479&mach=146 see APV here]
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| [http://kemibrug.dk/KBA/CAS/100648/?lang=da&show_KBA=1&portaldesign=1 see KBA here]
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| |[http://www.labmanager.danchip.dtu.dk/d4Show.php?id=1897&mach=64 see APV here]
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| [http://kemibrug.dk/KBA/CAS/106534/?show_KBA=1&portaldesign=1 see KBA here]
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|
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| |-valign="top"
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| |'''Chemical solution'''
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| |BHF
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| |5% HF
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| |40% HF
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| |BHF with wetting agent
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| |-valign="top"
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| |'''Process temperature'''
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| |Room temperature
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| |Room temperature
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| |Room temperature
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| |Room temperature
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| |-valign="top"
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| |'''Possible masking materials'''
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| *Photoresist
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| *Silicon nitride
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| *PolySi
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| *Blue film
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|
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| In RCA bench:
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| *No masking material
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| In '''plastic''' beaker or PP-bath in the fume hood in cleanroom 2:
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| *Photoresist
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| *Silicon nitride
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| *PolySi
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| *Blue film
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|
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| In RCA bench:
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| *No masking material
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| In '''plastic''' beaker with magnetic stirrer in the fume hood in cleanroom 2:
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| *Photoresist
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| *Silicon nitride (Only on quartz wafers)
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| *PolySi(Only on quartz wafers)
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| *Blue film
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| *Chromium and gold
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| *Photoresist
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| *Silicon nitride
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| *PolySi
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| *Blue film
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| |-valign="top"
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| |'''Etch rate'''
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| *Wet thermal oxide:~80nm/min
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| *PECVD1 (standard):~147nm/min
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| *TEOS:~265nm/min
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| *Stoichiometric Si3N4: ~0.75nm/min (Morten Bo Mikkelsen, March 2013)
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| *Low stress Si3N4: ~0.38 nm/min (Eric Jensen, Juni 2013)
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| *Wet thermal oxide:~25nm/min
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| *PECVD1 (standard):~87nm/min
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| *TEOS:~153nm/min
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| *Boronfloat and quartz: ~3-4 μm/min
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| A little higher etch rates than BHF
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| |-valign="top"
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| |'''[[#Life_time_of_the_photoresist_and_blue_film_in_BHF|Life time of the photoresist]]'''
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| |~½ hour
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| |~½ hour
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| |~½ hour
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| |~½ hour
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| |-valign="top"
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| |'''Batch size'''
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| Plastic beaker:
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| *1-5 wafer of 4" at a time
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| PP-bath:
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| *1-25 wafers of 4" at a time
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| BHF-bath in cleanroom 3:
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| *1-25 wafers of 4" at a time
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| BHF-bath in cleanroom 4:
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| *1-25 wafers of 4" or 6" at a time
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| BHF-bath in RCA bench:
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| *1-25 wafers of 4" or 6" at a time
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| Plastic beaker:
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| *1-5 wafer of 4" at a time
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| PP-bath:
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| *1-25 wafers of 4" at a time
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| HF-bath in RCA bench:
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| *1-25 wafers of 4" or 6" at a time
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| 1-7 wafer of 4" at a time
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| 1-25 wafer of 4" at a time
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| |-
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| |'''Size of substrate'''
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| 4"-6" wafers
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| 2"-6" wafers
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| 4" wafers
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| 4" wafers
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| |-valign="top"
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| |'''Allowed materials'''
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| In plastic beaker or PP-bath in the fume hood in cleanroom 2:
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| *All materials
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| BHF-bath in cleanroom 3:
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| *Silicon
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| *Silicon nitrides
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| *Silicon oxides
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| *Photoresist
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| BHF-bath in the RCA bench:
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| *Only wafers with phosphor glass or boron glass that comes directly from one of the furnaces in stack A.
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| In plastic beaker or PP-bath in the fume hood in cleanroom 2:
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| *All materials
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| HF-bath in RCA bench:
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| *Only wafers that are being RCA cleaned
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| In plastic beaker in the fume hood in cleanroom 2:
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| *All materials
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| *Silicon
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| *Silicon nitrides
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| *Silicon oxides
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| *Photoresist
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| |}
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|
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| ==Life time of the photoresist and blue film in BHF==
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| Photoresist delaminates from the substrate in BHF. For standard photoresist this process starts after about or less than ½ hour but the time can vary with resist pattern. It starts by under etching the photoresist at the edges. The life time can be prolonged a little to ½ hour - 40 minutes if the photoresist is baked at 120<sup>o</sup>C.
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|
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| Blue film also has a limited life time in BHF. Blue film is mainly used for back side protecting the wafer while etching on the front side. The life time of Blue film is also about ½ hour.
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|
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|
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| ==KOH etching baths==
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| =<span style="background:#FF2800">THIS PAGE IS UNDER CONSTRUCTION</span>[[image:Under_construction.png|200px]]=
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| |} | | |} |
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| | ==Life time of the photoresist and blue film in BHF== |
| | Photoresist delaminates from the substrate in BHF. For standard photoresist this process starts after about or less than ½ hour but the time can vary with resist pattern. It starts by under etching the photoresist at the edges. The life time can be prolonged a little to ½ hour - 40 minutes if the photoresist is baked at 120<sup>o</sup>C. |
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| | Blue film also has a limited life time in BHF. Blue film is mainly used for back side protecting the wafer while etching on the front side. The life time of Blue film is also about ½ hour. |
