Oxford Instruments – PlasmaPro100 Cobra

Restrictions and Precautions

I. Tool description

Oxford PlasmaPro100 Cobra offers large range materials etching possibility.

It primarily targets etching of metals (Al & Ti Alloys) with chlorine chemistry, but it can also etch silicon and its insulators (SiO2, Si3N4 and SiC) with fluorine/carbonate chemistry and some polymers with oxygen chemistry.

Technological advantages of this equipment are the followings:

  • Full wafer 100mm with fast pump/vent loading track
  • High density plasma of ICP (Inductively Coupled Plasma ) type
  • An electrostatic clamping and biasing chuck controlled in temperature (20°C to 60°C)
  • 8 digital Mass Flow Controllers (MFC) for the following gas : O(100sccm), O(10sccm), SF6, CF4, BCl3, Ar, Cl2 and HBr
  • Laser reflectometry/interferometry end-point-detection
  • Optical Emission Spectroscopy (EOS) end-point-detection

II. Standard processes

Material to etchProcess nameMaskEtch rate (nm/min)Chemistry
Al*, Ti, TiNAl_Ti_TiN_etchPRAl 340
Ti 250
PR 300
Cl2/BCl3
Al*, Ti, TiNAl_etch_w-breakthroughPRAl 510
PR 250
SiO2 50
BCl3 (BT)
Cl2 (main)
SiSi_etchPR
SiO2
Si 370
PR 430
BARC DUV42P 120
Cl2
SiO2, Si3N4SiO2_Si3N4_etchPRSiO2 175
Si 220
PR 332
BARC DUV42P 120
CF4
SiO2, Si3N4SiO2_Si3N4_RIEPRSiO2 45
Si 55
PR 25
BARC DUV42P 50
CF4/Ar
PolyimidePI_etch_O2-ArSiO2PI 2’550
SiO2 20
O2/Ar
Al2O3Sapphire_etchPRAl2O3 ALD 50
Al2O3 Sputtered 90
PR 415
Cl2/BCl3/Ar

*Aluminum post-etch treatment

After Aluminum etch, corrosion is an issue because of trapped Chlorine at patterns’ sidewalls: HCl creation will locally initiate as soon as the sample is at atmosphere and in contact with ambient humidity. 

In order to avoid slow corrosion of the Aluminum, straight after loadlock vent, get with no delay the wafers rinsed in a high volume of DI water (cascade or trickle tank on any of the benches of Zone2). This will force create HCl but will dilute/rinse it right away from the wafers.

Then proceed as soon as possible with full removal of the resist mask.

III. How to use the tool

Step-by-step usermanual

IV. Photos gallery