For Lift-Off processes, it is recommended to place copper plates on the backside of wafers to improve their thermal mass and limit their temperature rise.
Contents
- Introduction
- Equipement description
- Standard Recipes
- How to use the system
- Restrictions & Precautions
I. Introduction ↑
The EVA 760 is an equipment allowing the deposition of metallic layers on 100 mm or 150 mm wafers by evaporation.
The material is evaporated by heating up the crucible in which it is placed by electron beam.
II. Equipment description ↑
Dimensions and capabilities
In the EVA 760, 3 working distances source-substrates can be chosen and manually adjusted by the user:
- 450 mm : Preferred distance for Lift-Off processes.
- 350 mm
- 250 mm : Preferred for fast deposition rates.
The substrate holders are dome shape with different curvatures depending on the working distance selected. Each dome can receive 8 x 100 mm wafers or 5 x 150 mm wafer.
Evaporation systems
The EVA 760 is equipped with an electron gun: Ferrotec EV M-8 ; 10 kW , 6 pockets.
Film thickness measurement
The film thickness is determined by following the change in frequency of a quartz crystal. This change is due to the growing mass of material on top of its surface. Thanks to some calibrations, the variation can be related to the thickness of the film deposited.
- Deposition controller : Inficon IC/6.
- 1 x carousel with 6 quartz crystals QSK 621 at the center of the substrate holder.
- 3 x Quartz crystal on sides of the chamber (One placed bellow the shutter to check to deposition rate before the opening and the coating of samples).
Pumping
To reach high vacuum, the system is equipped with a cryogenic pump.
- Primary dry pump.
- Cryogenic pump: Cryopump CTI OnBoard 400.
- Pumping capabilities:
- N2 = 6000 l/s
- H2O = 17 500 l/s
Pressure
The pressure in the system is measured by:
- 1 x Capacitance Diaphragm Gauge: INFICON CDG045D
- 1 x Full RAnge Gauge: INFICON BCG450
III. Standard recipes ↑
The EVA 760 is equipped with a system allowing to initiation of a glow discharge if needed. Its main purpose is to clean samples from the water vapor absorbed by surface and the hydrocarbon coming from the environment.
Only thicknesses (for each layer) can be changed. For recipe creation, please contact responsibles of the tool.
For details concerning precious material billing, see Processing fees page.
IV . How to use the system ↑
All the actions to operate the system are detailed in the user manual.
V. Restrictions & Precautions ↑
- Reminder : It is recommended to place copper plates on the backside of wafers to improve their thermal mass and limit their temperature rise especially for Lift-Off processes.
- Allowed substrates are Silicon, Sapphire, Glass (Quartz, Pyrex, Float). For any other substrates please confirm with CMi staff.