Plade Oxide

Preliminary and fundamental remark:

  • SAFETY OPERATOR MANUAL TO OPERATE ON CMi WETBENCHES  (HERE)

Contents

  1. Introduction
  2. Standards at CMi
  3. Modus operandi
  4. Pictures

I. Introduction

The baths of the Plade Oxide in zone 2 are arranged as depicted in figure 1.

The baths are filled with different HF mixtures targeting etching of silicon oxide, pyrex or float glass.

Depending on the application, the bath may be fitted with a temperature adjusting system and with a circulating pumping system to activate etching.

FFR: Fast Fill Rinse (rough rinsing)
TT: Trickle Tank (fine rinsing)
Figure 1: Schematic of the Plade Oxide bench
Bath N° 0 1 2 3
Contents Diluted HF (1% or 10%, on demand)

Static bath, room temperature.

BHF 7:1

Circulating bath, room temperature

BHF 7:1

Circulating bath, room temperature

HF 10%

Circulating bath, heating system

Application Native oxide

Metallics-free (clean bath)

Pyrex
Float glass
SiO2, Al2O3, HfO2

Not microelectronic compatible

SiO2

Metallics-free (clean bath)

Pyrex
Float glass
SiO2

Not microelectronic compatible

II. Standards at CMi

Material to etch Bath N° Chemicals Mask Etch rates (nm/min) T (°C)
SiO2 0
Metallics-free (clean bath)
Diluted HF PR 5 WetOx (HF1%) RT
Pyrex
Float glass
SiO2, Al2O3, HfO2
1
Not microelectronic compatible
BHF
NH4F 40% + HF 50%
7:1
Cr
PR

77 WetOx
30 Pyrex
70 Al2O3 (ALD)
1.5 HfO2
RT
SiO2

2
Metallics-free (clean bath)
BHF
NH4F 40% + HF 50%
7:1
PR 77 WetOx
86 DryOx
80 Fused Silica
250-300 LAB HRI
225 LTO no densification
120 LTO with densification
262 TEOS no densification
470 PSG
250 SiO2 Spider
RT
Pyrex
Float glass
SiO2
3
Not microelectronic compatible

HF(49%):H2O
1:4

Cr/PR
Cr/Au/Cr/Au
380 Pyrex
175 Fused Silica
25
40

III. Modus Operandi

  1. Login on the Plade Oxide using zone 2 computer
  2. If applicable, activate the circulating system and the heating system after having checked/changed the set point. If working at room temperature, there is no need to activate the heating system
  3. Adjust the timer according to the etch rate and the wanted result
  4. Load the wafers in one of the dedicated Teflon carrier and put the handle on
  5. Full protection is now required (apron, face shield, chemical gloves) before going further
  6. Once the wanted temperature is reached, open the lid of the bath and gently plunge the carrier into it
  7. Start the timer (with clean hand)
  8. Rinse the gloves and gently clean the bath’s surroundings with a moist paper (several cleanings/rinsings are necessary)
  9. Wait the end of the etching. Remove the individual protective equipment if waiting time is long. Please fill-in a chemical label to inform other users about your running process
  10. If needed, get ready with the individual protective equipment a few minutes before etching is supposed to finish
  11. A buzzer indicates the end; press once on the timer button to stop the buzzer
  12. Open the FFR lid and gently transfer the Teflon carrier from the etching bath to FFR
  13. Activate the FFR button
  14. If applicable, stop the heating system and the circulating system of etching bath
  15. During FFR, rinse the gloves and gently clean the etching bath’s surroundings with a moist paper (several cleanings/rinsings are necessary)
  16. When FFR is finished, switch the Teflon carrier to the Trickle Tank TT
  17. Once resistivity is reached (~12 Mohm.cm), put the carrier in the spin rinser and dryer SRD (the carrier’s handle must be removed)
  18. A recipe is already selected. Just press STOP and the START
  19. When the SRD is finished, get the wafers back and put the carrier where it belongs
  20. Carefully check the cleanliness of the wetbench before taking off the chemical protection (apron, face shield, chemical gloves)
  21. Perform wetbench logout on zone 2 computer

 

Any droplets of any kind MUST be removed from the wetbench before leaving it. Suspicious droplets must be cleared using a moist paper (2 to 3 cleanings/rinsings are necessary) and remaining water droplets must be removed with absorbent paper.

IV. Pictures