Wet Processing: Which Material is Best?

Process Control, Safety, and Consistency
Polypropylene
  • Economical plastic with broad chemical compatibility
  • Ideal for wet processing station panels
  • Loses some chemical resistance at high temperatures
  • Suitable for HF and KOH processes
Quartz
  • The preferred material for ultra-pure applications
  • Provides greater uniformity in heat transfer than plastic baths—ideal for very tight temperature control
  • Suitable for most chemicals (but not HF acid)
  • Hard surfaces won’t scuff, stain, or absorb impurities
PVDF (polyvinyldilene fluoride)
  • Broader range of chemical resistance than polypropylene
  • Suitable for high process temperatures
  • Ideal for HF and BOE processes at high temperatures
PTFE (Teflon®)
  • Resistant to an extremely wide range of chemicals
  • Perfect for KOH and HF acid (which etch quartz)
  • Softer than quartz, so care must be taken to avoid scuffing, staining

Terra’s comprehensive range of constant-temperature baths, etching baths, dump risers, and other processing equipment is ideally suited for the high-purity requirements of the semiconductor industry. Microprocessor controls ensure the integrity of your operations.

The chart below indicates the baths best suited for common semiconductor operations. Once you select the equipment that meets your requirements, a Terra process engineer will help configure a turnkey solution.

Product Application Chart
Commercial or Generic NameProcessChemical CompositionConcentrationTypical TemperatureRecommended Product
Aqua RegiaGold EtchantHydrochloric Acid (HCl)
Nitric Acid (HNO3)
75%
25%
90°C Series
Buffered Oxide
Etch (BOE)
Etch SiO2Ammonium Fluoride (NH4F) Aqueous
Hydrofluoric Acid (HF) Aqueous
40%15-40°C
Ambient
A Series
RCe Series
CP8EtchNitric Acid (HNO3)
Hydrofluoric Acid (HF)
 AmbientA Series
Etch (Indium)
Molybdenum Platinum
Nichrome
EtchHydrochloric Acid (HCl) Aqueous
Nitric Acid (HNO3)
37-38%
70-71%
 QA Series
Metal EtchEtch A,
AlSi Al Si Cu
Phosphoric Acid (H3PO4)
Acetic Acid (CH3COOH)
Nitric Acid (HNO3)
85-87%30-60°CQA Series
Nitride EtchEtchPhosphoric Acid (H3PO4)
DI Water (H20)
85-87%
15-13%
150-185°CNb Series
Organic StripperResist RemovalPRS-1000
S-43
Lozolin
No Phenol-922
Full strengthRoom Temperature
120°C
Nb Series
Oxide Resist StripSiO2 Resist StrippingSulfuric Acid (H2SO4)
Ammonium Persulfate (NH4S2O2)
95-96%QA Series
Phenolic StripperResist RemovalJ100
Bermar 712D
R-10
 95-100°CC Series
Resist Series (Metalized)Resist RemovalChromic Sulfuric Acid (CrO3+H2SO4)  A Series
R.C.A. CleanPre-Diffusion Cleans
Quartzware
Step 1: Water
Hydrogen Peroxide (H2O2)
Ammonium Fuoride (NH4CH)
Step 2: DI Water (H2O)
Hydrogen Peroxide (H2O2)
Hydrochloric Acid (HCL)
40%75-85°CQa Series
Silicon EtchEtchAcetic Acid (CH3COOH)
Nitric Acid (HNO3)
HydroFuoric Acid (HF)
 AmbientA Series
Sirtl EtchEtchChromium Trioxide (CrO3)
DI Water (H20)
Hydrofluoric Acid (HF)
 AmbientA Series
Slope EtchEtchPhosphoric Acid (H3PO4)
Acetic Acid (CH3COOH)
Nitric Acid (HNO3)
 55°CQa Series
Standard Resist Strip (do not use w/aluminum)SiO2 Resist StripSulfuric Acid (H2SO4)
Hydrogen Peroxide (H2O2)
95-96%110-140°CQa Series
2:1 EtchEtchDI Water (H2O)
Hydrofuoric Acid (HF)
 AmbientA Series
Wafer RinsingRinsingDI Water (H2O)100%AmbientDR-Series
Particle Trapping Test