Update on 10/18/2002
Etch used for other Oxide/cleaning 
  Cleaning   - Acetone
  Note: Will leave residue if nnot used in conjunction with alcohol.

 - Isopropyl alcohol
  Note: Also available on air brush.

 - Methyl alcohol
  Note: Prefered to isopropyl.
  Removing Ink dots  - m-pyrol followed by a rinse in acetone followed by alcohol.
  Note: Some types of ink dots can be removed with just acetone followed by alcohol. 
  External print on 
  Ceramic packages		  - Warm J-100 resist strip in conjunction with mechanical removal.
  Organics  - O2 plasma ( 8 min, 200W)
   Note: Selectivity is excellent.
  Check: Optically. If metal remains either oxide was present on metal or etch was weak.
  Nitride passivation  - CF4 + O2 plasma (6 min Plasmod; 4 min TEGAL)
    Note: Mask all Au with Al tape, photoresist, or silicon grease. Plasma will etch SiO2. Be sure to purge
            chamber with gas prior to etching.
     Check: Bond pad area for line.
               Die color will chnage from yellow to clear although some Si3N4 initially appears to be clear. 
               Scribe line area for overetch.
 - Hot phosphoric (H2PO4) , 1-2 sec
    Note: Will attack metallization.
        Etch rate is 6.6 nm/min at 180 C
 - Boiling HPO3 (Attacks Al to some extent)
 CVD Oxide
passivation		   - BOE (Buffereed Oxide Etch) , 0.65 - 1.0 min
    Note: Will attack metallization.

  - 10% HF
     Note: HF will slightly attack metallization (rough appearance).
             Slight dip in 10% HF will "smooth" SiO2 for SEM examination.
             Underetch for internal probing.
             Device typically loses functionality after short wet etch (10 sec)
             Etchant containing HF will attack silver die attach and leave silver residue on die surface.
   Check: Bond pad for line. Don't be confused by rough bond pad metallization.
              Internal probe checking for continuity SEM examination. 
  IMD (SiO2)
  Inter Metal
Dielectric
  Ex: Metal 1 - Metal2 1 ILO		   - BOE
  - 10 % HF
  - Modified Oxide etch
     Check: Metal 2 to metal 1 contacts. Where metal 2 had crossed over metal 1.
     SEM analayis.
  ILO(Covered Metal)    - KOH (Room temp, 5 min)
     Check: Optical inspection
  ILO(Covered Poly)    - Dilute poly etch ( 20 sec)
     Check: Optically and with SEM at both ILO and poly level.
  Nitride   - KOH (Room temp, 5 min)
     Check: Bond pad areas. Optical inspection
  Polysilicon   - HF/HNO3/acetic acid
  Passivation glass   - NH4F/FHacetic acid  (Removes all glass layers. May attack Al, Cr and Ni