Download - Cambridge NanoTech Overview
Simplify the Science of ALD.
Cambridge NanoTech
Corporate Overview
August 2009
Cambridge NanoTech Inc. Confidential 2
Cambridge NanoTech ALD Systems
• All Cambridge NanoTech ALD Systems are controlled with a
convenient Labview-PC-USB interface.
• All ALD systems have hot walls with cross-flow precursor
deposition. N2
gas is used for high speed pulse-purge cycles.
• Prior to deposition, a substrate is inserted into the ALD reactor,
and is heated usually between 50-400ºC.
Cambridge NanoTech Inc. Confidential 3
• Trimethyl Aluminum (TMA) reacts with the adsorbed
hydroxyl groups, producing methane as the reaction
product.
Tri-methylaluminumAl(CH3)3(g)
CH
H
H
H
Al
O
Hydroxyl (OH)from surfaceadsorbed H2O
Methyl group(CH3)
Substrate surface (e.g. Si)
Reaction of TMA with OH
CH
H
H
H
Al
O
Methane reactionproduct (CH4)
Substrate surface (e.g. Si)
HC
HH
H
C
In air H2O vapor is adsorbed on most surfaces,
forming a hydroxyl group. With silicon this forms:
Si-O-H (s). After placing the substrate in the
reactor, Trimethyl Aluminum (TMA) is pulsed into
the reaction chamber.
Trimethyl Aluminum (TMA) reacts with the
adsorbed hydroxyl groups, producing methane as
the reaction product.
Al(CH3)3 (g) + : Si-O-H (s) :Si-O-Al(CH3)2 (s) + CH4
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 4
• Trimethyl Aluminum (TMA) reacts with the adsorbed
hydroxyl groups, producing methane as the reaction
product.
Al(CH3)3 (g) + : Si-O-H (s) :Si-O-Al(CH3)2 (s) + CH4
C
H
H
H
H
Al
O
Reaction ofTMA with OH
Methane reactionproduct CH4
H
HH
HH C
C
Substrate surface (e.g. Si)
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 5
• Trimethyl Aluminum (TMA) reacts with the adsorbed
hydroxyl groups, until the surface is passivated. TMA does
not react with itself, terminating the reaction to one layer.
This causes the perfect uniformity of ALD. The excess TMA
is pumped away with the methane reaction product.
C
HH
Al
O
Excess TMA Methane reactionproduct CH4
HH C
Substrate surface (e.g. Si)
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 6
• After the TMA and methane reaction product is pumped
away, water vapor (H2O) is pulsed into the reaction chamber.
C
HH
Al
O
H2O
HH C
OHH
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 7
• H2O reacts with the dangling methyl groups on the new
surface forming aluminum-oxygen (AI-O) bridges and
hydroxyl surface groups, waiting for a new TMA pulse.
Again, methane is the reaction product.
2 H2O (g) + :Si-O-Al(CH3)2 (s) :Si-O-Al(OH)2 (s) + 2 CH4
New hydroxyl group
Oxygen bridges
Methane reaction product
Methane reaction product H
Al
O
OO
Al Al
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 8
• The reaction product methane is pumped away. Excess H2O
vapor does not react with the hydroxyl surface groups, again
causing perfect passivation to one atomic layer.
H
Al
O
OO O
Al Al
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 9
• One TMA and one H2O vapor pulse form one cycle. Here
three cycles are shown, with approximately 1 Angstrom per
cycle. Each cycle including pulsing and pumping takes, e.g.
3 sec.
O
H
Al Al Al
HH
OO
O OO OO
Al Al AlO O
O OO
Al Al AlO O
O OO
Al(CH3)3 (g) + :Al-O-H (s) :Al-O-Al(CH3)2 (s) + CH4
2 H2O (g) + :O-Al(CH3)2 (s) :Al-O-Al(OH)2 (s) + 2 CH4
Two reaction steps
in each cycle:
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 10
• The saturative chemisorption of each layer and its
subsequent monolayer passivation in each cycle, allows
excellent uniformity into high aspect ratio 3D structures,
such as DRAM trenches, MEMS devices, around particles, etc.
ALD Cycle for Al2O
3 Deposition
Cambridge NanoTech Inc. Confidential 11
ALD Deposition Advantages
• Thickness determined simply by number of cycles
• Precursors are saturatively chemisorbed => stoichiometric
films with large area uniformity and 3D conformality
• Relatively insensitive to dust (film grows underneath dust
particles)
• Intrinsic deposition uniformity and small source size =>
easy scaling
• Nanolaminates and mixed oxides possible
• Low temperature deposition possible (RT-400 ºC)
• Gentle deposition process for sensitive substrates
Alternating reactant exposure creates unique
properties of deposited coatings:
Cambridge NanoTech Inc. Confidential 12
Cambridge NanoTech ALD Systems
Savannah Fiji Phoenix
• Savannah - Thermal ALD System for R&D
– More than 100 systems sold
• Fiji – Plasma ALD System for R&D
– Next generation plasma ALD system
• Phoenix – Batch Production Thermal ALD System
– Batch production for Gen 2 substrates and wafers
• Tahiti – Large Surface Area Production Thermal ALD System
– Stackable chambers for Gen 4.5 substrates
Tahiti
Cambridge NanoTech Inc. Confidential 13
Savannah ALD Systems
Savannah S100 Savannah S200 Savannah S300
• World’s most popular ALD system for R&D
• Great films and easy to use
– System set up in under 3 hours
– Intuitive user interface very easy to learn
– Recipes included
Cambridge NanoTech Inc. Confidential 14
Patent Pending ALD ShieldTM Trap
Cambridge NanoTech’s highconductance hot foil ALD trapforms a uniform solid coatinguntil the precursor is depleted.Traps can be cleaned after 100µm of coating.
Flow direction
Coating
No coating
Cambridge NanoTech Inc. Confidential 15
• Revolutionary reactor design built from ALD
principals, NOT a converted CVD chamber:
– Contoured shape for laminar flow and uniform
depositions
– Design eliminates gate valves in the reactor
– Close mixing of precursor and plasma gases
• Based on world class Savannah ALD system
– Proven precursor delivery system
– Integrated ALD Shield vapor trap
• Modular design and many configurations
– Single and dual chamber configurations available
– Options include load lock, turbo pumps, and
automatic pressure control (APC)
Fiji: Next Gen Plasma ALD System
Cambridge NanoTech Inc. Confidential 16
Sample Fiji Configurations
Single Chamber with
Load Lock
Dual Chamber Dual Chamber with
Cleanroom Façade
Also Available: Dual chamber with load locks, Single chamber with
clean room façade, and optional analysis ports in reaction chamber
Cambridge NanoTech Inc. Confidential 17
Phoenix System Overview
• Batch ALD production system– 5 GEN 2 substrates (370x470 mm)– 52 wafers: 200 mm– 78 wafers: 150 mm– Large objects
• Deposition temperature: 85–285 C
• Uniformity < 3% 2-sigma (Al2O3)
• Small footprint: 700x700 mm
• Optimized for low maintenance– stainless steel liner and trap easily
exchanged for periodic cleaning– Exchange time approx. 1 hour
• Patent pending trap prevents coating inside the pumping line and pump decreasing pumping line and pump maintenance
Phoenix Batch ALD System
Cambridge NanoTech Inc. Confidential 18
Tahiti System Overview
• Tahiti Large Surface Area production system– 2 Gen 4.5 substrates– Scalable to accommodate Gen 5 substrates
and larger
• Uniformity < 5% 3-sigma (Al2O3)
• Dual stacked chambers saves cleanroom space
• Optimized for low maintenance– Stainless steel liner and trap easily
exchanged for periodic cleaning
• Patent pending trap prevents coating inside the pumping line and pump decreasing pumping line and pump maintenance
• Automation-ready with easy network connectivity and on-board diagnostics.
Tahiti ALD System
Cambridge NanoTech Inc. Confidential 19
Cambridge NanoTech Summary
See Website for additional information
www.cambridgenanotech.com
• Cambridge NanoTech is a world leader in ALD technology
– World-class ALD scientist led by Dr. Jill Becker, Founder
– Leading ALD research with association with Harvard Univ.
• Leader in ALD R&D systems with over 150 Savannahs worldwide
– Many satisfied customers and references
• Developed Phoenix and Fiji ALD systems under contract with CNT
customers
– Leading Semiconductor manufacturer hired CNT to develop
the Phoenix ALD production system
– Leading R&D Institute hired CNT to develop the next
generation plasma ALD system - Fiji