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.


• 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)


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



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


ALD Cycle for Al2O

3 Deposition



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


ALD Cycle for Al2O

3 Deposition


• 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


• 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


• 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


• 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


• 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


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 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


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


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


• 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


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


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


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 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

Download - Cambridge NanoTech Overview

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