2. Software description cosma pulse

3. COSMA Pulse is a control software that broadens conventional tools’ process capabilities to enable time-multiplexed processes

4. Cost effective upgrade
Cosma pulse benefits
11/22/2018
Advanced Process Control
Enhanced functionality
ALL PARAMETERS
CAN BE CONTROLLED AND PULSED
Short step times
10 ms
DATA AQUISITION
Cost effective upgrade
FOR CORIAL SYSTEMS INSTALLED AT CUSTOMERS’ SITES
Advanced process editing
SET TO, RAMP TO AND PULSE FUNCTIONS
+/-0,1%
ACCURACY
ON BIAS FINE TUNING
COSMA Pulse

5. Process editing
11/22/2018
Intelligent process control, using not only the standard “SET to” and RAMP to” functions, but also an added “PULSE” function
Control and Pulse of any process parameter (such as gas flow rate, RF and ICP power, working pressure, etc.), with a minimum pulsing period of 10 milliseconds
Edit, store, use, and duplicate process recipes with the COSMA Pulse unique user interface
COSMA Pulse

6. Process editing Details of the pulsed parameter setting
11/22/2018
Show/close all the details of the pulsed parameters
Show the pulsed parameters
Mode: Pulsed
Details of the pulsed parameter setting
COSMA Pulse

7. Process adjustment
11/22/2018
All process parameters can be pulsed and adjusted during process execution
Details of the pulsed parameter setting
Real-time process adjustment
COSMA Pulse

8. Multiple user access rights
Process OPERATIOn
11/22/2018
Multiple user access rights
PASSWORD CONTROLLED LOGIN WITH DIFFERENT LEVELS OF USER ACCESS
Real time process data display
ALL PROCESS PARAMTERS CAN BE MONITORED SIMULTANEOUSLY IN REAL TIME DURING PROCESS EXECUTION
Process reproducibility
TIGHT CONTROL AND MONITORING OF PROCESS STEPS
Multistep recipes
LOOPS WITH AUTOMATED TRANSITION TO THE NEXT PROCESS STEP BASED ON SIGNALS FROM END POINT DETECTORS
COSMA Pulse

9. Cosma pulse application #1 DRIE

10. To alternate between each step,
Drie of silicon
11/22/2018
Process Steps
CORIAL Bosch-like process has 3 steps
step 1 - Polymer deposition by C4F8 plasma
step 2 - Polymer etching  by SF6 plasma
step 3 - Silicon etching with 20W of RF power, which was used to increase the silicon etching rate
To alternate between each step,
COSMA pulse software is required for pulsing consecutively C4F8 gas flow, SF6 gas flow, LF and RF power
COSMA Pulse

11. Drie of silicon
11/22/2018
Advantages
Precise control of the etch profile, fast etch rates, and excellent etch uniformity
COSMA Pulse

12. Results obtained with 100 mm wafer, 20% Si open area
Drie of silicon
11/22/2018
Performances
Feature size
(µm)
Etched depth
Aspect ratio
Etch rate
(µm/min)
Mask
Selectivity
(vs. mask)
Ø250
Through wafer
1:2
> 3.0
SiO2
330
Ø100
515
1:5
> 2.9 PR 85
Ø20
280
1:14
> 1.5
155 Ø5
180
1:35
> 1.0
100
Results obtained with 100 mm wafer, 20% Si open area
COSMA Pulse

13. Cosma pulse application #2 atomic scale etching

14. Atomic scale process reminder
11/22/2018
Process Steps
Adsorption step
Formation of reactive monolayer
Purge step
Evacuation of the excess adsorbent species
Desorption step
Exposure of the reactive monolayer to form volatile species
Cleaning the reactor of all species
KEREN J. KANARIK et. al., Moving atomic layer etch from lab to fab, Solid State Technology 2014
Applications of Atomic Scale Etching
Power and RF&MW electronics
R&D, nanotechnology
nm-scale IC technology…
COSMA Pulse

15. Atomic scale etching of silicon
11/22/2018
Process Steps
Advanced tuning of RF pulsing (red) to control ion energy
Independent and rapid pulsing of chlorine (blue) and argon (green) flows during adsorption and desorption steps
The laser signal shows an etch rate of
1.68 Å/cycle
COSMA Pulse

16. Atomic scale etching of silicon
11/22/2018
Performances
Si wafer before etching
Roughness = nm
Si wafer after etching of 0.5 µm
Roughness = nm
COSMA Pulse

17. Atomic scale etching of gan
11/22/2018
Process Steps
CORIAL process steps for GaN recess etch
Process steps
RF Power
(W)
Pressure
(mT)
Chemistry
Pulsed parameters
Step 1 - Adsorption 10 25
Cl2 Ar
Chlorine
Step 2 - Purge
Step 3 - Desorption
100
RF power
Weak RF plasma activation of Cl2 is used to enhance chlorination of GaN surface
Desorption of by-products is achieved in RIE mode by Ar+
COSMA Pulse

18. CORIAL process steps for GaN recess etch
Atomic scale etching of gan
11/22/2018
Process Steps
CORIAL process steps for GaN recess etch
COSMA Pulse

19. Atomic scale etching of gan
11/22/2018
Performances
2’’ Sapphire wafer
AlxGa1-xN / AlxGa1-xN <Si> / AlN stack
GaN
50 A
1.2 µm
Recess etch
CORIAL process performances
Process
Total process duration
(min)
Number of cycles
Period
(s)
Etch depth
(Å)
Etch rate
(Å/cycle)
(Å/min)
ALE GaN recess etch 20
300 6 50
0.4 4
COSMA Pulse

20. Atomic scale etching of gan
11/22/2018
Performances
HEMT Transistor performances before (left curves) and after recess etching (right curves)
Higher transconductance is obtained
No deterioration of the drain current is obtained after ALE-like recess etching
COSMA Pulse

21. Cosma pulse application #3 time-multiplexed deposition

22. Time-multiplexed deposition of sio2
11/22/2018
Process Steps
Precursor
a-Si deposition
Purge
N2O plasma oxidation
4-step process
step 1 – a-Si deposition by SiH4/Ar chemistry
step 2 - Purge
step 3 – a-Si oxidation by N2O
step 4 – Purge
COSMA Pulse

23. Time-multiplexed deposition of sio2
11/22/2018
Process Steps
a-Si deposition 2.5s
Period 10s
N2O oxidation 5.5s
Time (s)
2,5
3,5 9 10
Purge 1s RF
N2O
SiH4
0,1 3
500
1000
Parameter: SiH4
Mode: Pulsed
Value 1: 3
Value 2: 0,1
Period: ms
Cycle: 25%
Delay: 0 ms
Parameter: Ar
Mode: Pulsed
Value 1: 500
Value 2: 1000
Period: ms
Cycle: 55%
Delay: ms
Purge 1s Ar
Parameter: N2O
Mode: Pulsed
Value 1: 500
Value 2: 0,1
Period: ms
Cycle: 55%
Delay: ms
Parameter: RF
Mode: Pulsed
Value 1: 100
Value 2: 50
Period: ms
Cycle: 55%
Delay: ms
100 50
COSMA Pulse

24. Time-multiplexed deposition of sio2
11/22/2018
Performances
Process steps
RF Power
(W) Ar
(sccm)
N2O
SiH4
Time
(s)
Deposition rate
(Å/cycle)
(nm/min)
R.I.
Uniformity on 4”
(±%)
Stress
(Mpa)
Step 1 - Precursor 50
1000
0.1 3
2,5 7
4,2
1,465
0,7
-227
Step 2 - Purge
0,1 1
Step 3 - Oxidation
100
500
5,5
Step 4 - Purge
COSMA Pulse