Wet Etching Recipes

From UCSB Nanofab Wiki
Jump to: navigation, search

See the Master Wet Etching Table at the bottom of this page for wet-etch rates in various experiments we have tested.

References

  1. Etch rates for Micromachining Processing (IEEE Jnl. MEMS, 1996) - includes tables of etch rates of numerous metals vs. various wet and dry etchants.
  2. Etch rates for micromachining-Part II (IEEE Jnl. MEMS, 2003) - expanded tables containing resists, dielectrics, metals and semiconductors vs. many wet etch chemicals.
  3. Guide to references on III±V semiconductor chemical etching - exhaustive list of wet etchants for etching various semiconductors, including selective etches.
  4. Transene's Chemical Compatibility Chart provides a useful quick-reference for which Transene etchants attack which materials.
    1. As a side-note, Transene provides many pre-mixed solutions that you can order, saving you the time and uncertainty of measuring/mixing such chemicals yourself. Make sure you check with us before ordering so we know how to handle the chemical before it arrives.

Compound Semiconductor Etching

Guide to references on III±V semiconductor chemical etching

Please add any confirmed etches from this reference to the The Master Table of Wet Etching (Include All Materials).

Metal Etching

Silicon etching

Etch rates for micromachining processing

Etch rates for micromachining processing-part II

Please add any confirmed etches from this reference to the The Master Table of Wet Etching (Include All Materials).

Dielectric etching

Organic removal

Gold Plating

Chemi-Mechanical Polishing (CMP)

Example Wet Etching Table

How to use the Master Table of Wet Etching:

When entering a new etch into the table make a row for every etchant used in the solution such that the information can be sorted by etchant. For example, the InP etch HCl:H3PO4(1:3) and H3PO4:HCl(3:1). Likewise, if etch is known to be selective to multiple materials the etch should have a row for each material. For example HCl:H3PO4(1:3) is selective to both InGaAs and InGaAsP.

This multiple entry method may seem laborious for the person entering a new etch, however the power of sorting by selective materials and chemicals in a table with all materials is great.

Material Etchant Rate (nm/min) Anisotropy Selective to Selectivity Ref. Notes Confirmed by Extra column
InP HCl:H3PO4(1:3) ~1000 Highly InGaAs High Lamponi (p.102) Example Jon Doe Example
InP HCl:H3PO4(1:3) ~1000 Highly InGaAsP High Lamponi (p.102) Example Jon Doe Example
InP H3PO4:HCl(3:1) ~1000 Highly InGaAs High Lamponi (p.102) Example Jon Doe Example
InP H3PO4:HCl(3:1) ~1000 Highly InGaAsP High Lamponi (p.102) Example Jon Doe Example

The Master Table of Wet Etching (Include All Materials)

Use the ↑ ↓ Arrows in the header row to sort the entire table by material, selectivity, etchant etc.

Material Etchant Rate (nm/min) Anisotropy Selective to Selectivity Ref. Notes Confirmed by Extra Notes
InP HCl:H3PO4 (1:3) ~1000 Highly InGaAs High Lamponi (p.102) Example Jon Doe Example
InP HCl:H3PO4 (1:3) ~1000 Highly InGaAsP High Lamponi (p.102) Example Jon Doe Example
InP H3PO4:HCl (3:1) ~1000 Highly InGaAs High Lamponi (p.102) Example Jon Doe Example
InP H3PO4:HCl (3:1) ~1000 Highly InGaAsP High Lamponi (p.102) Example Jon Doe Example
Al2O3 (ALD Plasma 300C) Developer: 300MIF ~1.6 None Most non-Al Materials. High Measured in-house Rate slows with time. JTB Example
Al2O3 (ALD Plasma 300C) Developer: 400K ~2.2 None Most non-Al Materials. High Measured in-house Rate slows with time. JTB Example
Al2O3 (ALD Plasma 300C) Developer: 400K (1:4) ~1.6 None Most non-Al Materials. High Measured in-house Rate slows with time. JTB Example
Al2O3 (ALD Plasma 300C) NH4OH:H2O2:H2O (1:2:50) ~<0.5 Measured in-house Rate slows with time JTB Example
Al2O3 (IBD) HF ("Buffered HF Improved", Transene) ~170 None Photoresist High Measured in-house May need to increase adhesion with thin SiO2 layer, and 100°C baked HMDS. Biljana Stamenic 2017-12
Al2O3 (IBD) Developer: 726 MiF 3.5 None Most non-Al Materials. Measured in-house Demis D. John 2017-11
Al2O3 (AJA#4) Developer: 300 MiF 4.30 None Most non-Al Materials. Measured in-house Demis D. John 2018-02
SiO2 (PECVD #1) HF ("Buffered HF Improved", Transene) ~500 None Photoresist High Measured in-house May need to increase adhesion with 100°C baked HMDS. Biljana Stamenic 2017
SiO2 (PECVD #2) HF ("Buffered HF Improved", Transene) ~500 None Photoresist High Measured in-house May need to increase adhesion with 100°C baked HMDS. Biljana Stamenic 2017
SiO2 (IBD) HF ("Buffered HF Improved", Transene) ~350 None Photoresist High Measured in-house Biljana Stamenic 2016
Si3N4 (PECVD#1) HF ("Buffered HF Improved", Transene) 85 None Photoresist High Measured in-house Biljana Stamenic 2018-04
Si3N4 (PECVD#2) HF ("Buffered HF Improved", Transene) 35–45 None Photoresist High Measured in-house Biljana Stamenic 2018-05
Si3N4 Low-Stress (PECVD#2) HF ("Buffered HF Improved", Transene) 35–50 None Photoresist High Measured in-house Biljana Stamenic 2018-05
Si3N4 (IBD) HF ("Buffered HF Improved", Transene) 5–15 None Photoresist High Measured in-house Biljana Stamenic 2014
Ta2O5 (IBD) HF ("Buffered HF Improved", Transene) 0.4 None Photoresist High Measured in-house Biljana Stamenic 2016-12
TiO2 (IBD) HF ("Buffered HF Improved", Transene) 1.0–2.0 None Photoresist High Measured in-house Biljana Stamenic 2014-12
Si (<100> crystalline) KOH (45%) @ 87°C ~730 High, Crystallographic Si3N4 - any PECVD or LPCVD Nitride High Measured In-House Use Covered, Heated vertical bath (Bay 4). Slight Bubbler. Brian Thibeault 2017