real time etching end point monitors (oes & interferometer...

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Real Time Etching End Point MonitorsReal Time Etching End Point MonitorsReal Time Etching End Point MonitorsReal Time Etching End Point Monitors

(OES & Interferometer type)(OES & Interferometer type)(OES & Interferometer type)(OES & Interferometer type)

HORIBA SemiconductorHORIBA SemiconductorHORIBA SemiconductorHORIBA Semiconductor


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Softwares

Applications

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ProductsProductsProductsProducts


1983 2007

20001990

Digisem

Multisem

PlasmaScope

First generations Digisem

First generationsmonochromators

• 26 years experience in Process Control Field

MultiCPM

Camera

Fixed time

CCDEPD

Monochromator

EPD

SOFIE Instruments JOBIN YVON HORIBA

EV 140

OES type

2009EV-140 C(Windows)

History of HORIBA End Point Monitor 1/2


History of HORIBA End Point Monitor 2/2

2010DIGILEM-H

1986

DIGILEM DIGILEM-TILT

2004 2007

DIGILEM-CPM(Windows)

Interferometer type

LEM-CT 670 & 905 nm


� UV signal sensitivity enhancement:- UV range optimised spectrograph

design - Backside thin CCD- 2D sensor: 2048*64 pixels

� Robustness design for Process use：- Simple configuration, High reliability- FA grade PC configurable

� EPD real time control platform:- 20ms (min) sampling - EPD conditions setting by Flexible formula definition- Complete process engineer tool- Unique EPD algorithm for low open area

� Remote network capability- Coactivity with process tool with specified protocol

Feature of EV-140 C (OES)

Spectrograph ： Flat field concave holographic gratingFocal L. 140 mm)

Spectra range ： 200 - 800nmResolution ： <2.0nm @λ＝200-500nm

<2.5nm @λ＝500-800nmDetector ： Back thin CCD detector 2048 chMin sampling ： 20msFiber length ： 2m (Standard)Outline ： 137 x 257 x 156 mm (WxDxH)Weight ： 4.0 kgRemote ctrl ： Parallel I/O, RS232C, (TCP/I

End point (ETCH, Cleaning), Health Monitoring (ETCH, Cleaning, CVD)


Feature of LEM-CT (Laser Interferometry 670, 905 nm )

� CCD patented Laser Interferometer:

670 nm, 905 nm

Spot diameter : from 25 µ

� Requirement: Top window on the chamber

� Measures intensity changes of light reflected from the sample surface during etch or deposition process

� powerful endpoint algorithms that can be easily extended from simple to highly customized applications.

� Real Time Etch Rate and Etched Thickness

� Endpoint at a defined thickness

� End Point on remaining thickness

� Endpoint on interface,…

End point (ETCH, CVD)


� Spectrometer unit and additional light source unit can create Wide wavelength range of monitoring.

� 2048 channels of CCD sensor can make Multi channel & SimultaneousInterferometry measurement.

� Wafer view can be observed with same optical axis of monitoring.

� Wide variety of HORIBA unique Interferometer algorithm

� Reliable and simple hardware

� Stop Remain Thickness Function is available for GaN process (Option)

� Pattern recognition and auto positioning function is available (Option)

Feature of DIGILEM-H (Spectroscopic Interferometry)



System configuration (DIGILEM-H-UV/VS)

Cameraview

SensorHead

Spectrograph& PC

HgXe lamp

Control unitSample: installed on IPC etcher

LED illumination

Wafer

Plasma

System configuration (DIGILEM-H-UV/VS)

Cameraview

SensorHead

Spectrograph& PC

HgXe lamp

Control unitSample: installed on IPC etcher

LED illumination

Wafer

Plasma

DIGILEM-H configuration and specifications

Model : DIGILEM – H – UV - MN

� Model :� DIGILEM – H – UV – MN

� DIGILEM - H – UV - PR (Option)/ - AT (Option)

� DIGILEM – H – VS – MN

� DIGILEM – H – VS - PR (Option)/ - AT (Option)

� Light source unit :� Xe-Hg Lamp or Halogen Lamp

� Spot diameter: � 100-500 microns (Depends on the

camera to wafer distance)

� Light source wavelength :� Xe-Hg : 300-450 nm� Halogen : 400-700nm

� Spectrometer (EV-140 C) : � Resolution > 2.0nm (with 50 micron

slit)� Detector : 2048ch CCD � Optical fiber : 2 branch fiber x 6m� Illumination unit : LED unit



SoftwaresSoftwaresSoftwaresSoftwares


Runs Browser• Informations• View• Select for reprocessing• Backup• Lock•…

Quick & Unified Recipes Selector• Spectra real-time• Endpoint, Health monitoring• Interferometry

ALARMS• History

Lots Analyzer

MultiRun Viewer

Recipe List• Create• Modify• Set Id• Report•…

Run name Action Button: SIMULGo for

REPROCESSING

Action Button:Go

View last Run

currentMode

Display, WD

ScriptGo for AutomaticREPROCESSING

Change owner mode

Sigma-P, unique software whatever the sensor

• Kinetic modeler (Interferometry)• Autopattern (Optical Emission Spectroscopy)


Sigma-P, unique software whatever the sensor

Sigma_P (Real time software installed on all systems)

– One click button action

– User friendly recipe creation & optimisation

– Comprehensive reprocessing/Scripts capabilities

– Integrated SQL database for data management, Multi-runviewer & Statistics

– Full connectivity to cluster tools and factory host

–Manufacturing (24h/day 365/year operators & OEM)

– Process & Tool control: alarms, events follow-up, loopback

– Fab integration for distant desktop, in-fab alert notification

– Completed with Powerful Engineering Tools


Sigma-P, recipe editor

Tree View:

• Click a property to open its parameters• Add, Remove properties

Endpoint Property: Parameters appears in line

• Click on columns to modify parameters• Add line/remove line• Variable: easy to use in formula Editor: CURVi, CONDi, DECIi,…


Engineering softwares

Interferometer type

OES type

Recipe Designer (option on desktop only)(ENGINEERING TOOL)• Easy “semi automatic” way to go from spectra acquisition to Endpoint wavelengths selection using proprietary algorithms• « Automatic » Endpoint recipe creation usingnew mathematical algorithms• Import EPD recipe to Sigma_P in one click !

Kinetic Modeler (ENGINEERING TOOL)• Simulate layers piling• obtain theoritical interferometric curves• Save Reference & Import to Sigma_P in one click !


ApplicationsApplicationsApplicationsApplications


� Application Fields

� Semiconductor: memories (EDRam, MRam, Flash…), logic circuit devices

� Optoelectronic: telecommunications, laser diode,…

� MEMS: micropump, accelerometer, micromotor,…

� Compounds: LED

� Optical coatings, FPD, Failure analysis,…

� LCD --� Cleaning (Expensive gases economy)

� PV --� Uniformity during deposition (manage plasma condition), cleaning (NF3, F2), Etch (CxFy)

� …

In-Situ Process control applications


Interferometric ApplicationsInterferometric ApplicationsInterferometric ApplicationsInterferometric Applications

� Etch and Growth Rate

�Layer Thickness

� End Point Detection


Laser result features DIGILEM-H

A Layer

ＧａＡｓ

ＢLayer

ＭＱＷ

GaNGaNGaNGaN/MQW/MQW/MQW/MQWInterfaceInterfaceInterfaceInterface

End point

Measurement wavelength: λλλλ=550 nm

(Stop Remain Thickness function / Option)

Measurement wavelength: λλλλ=335nm

Red Laser device

Blue Laser device (GaN process)

Laser device, LED,…

Multiwavelength monitoring due to a wide range of multilayer stack


GaAs- GaAlAs optoelectronic features LEM-CT + EV-140

Cladding

layer

Buffer

layer

QW

Confinement

layer

Confinement

layer

Typical wafer structures ?

Example of wafer surface achieved

LD: Laser Diode - PD: PhotoDetector

GaAs buffer layer

Resist

p AlGaAs graded index

n AlGaAs graded index

p+ GaAs

4 QWs

n+ AlGaAs

GaAs substrate

905 nm

laser spot

Typical results obtained ?

Changes on interferometric signal: amplitude and period.

which allows to

1) measure etch rate in real-time

2) distinguish changes of layer composition into heterostructure

Interferometric and OES signals

GaAs/GaAlAs interface detection

Additionnally to Laser Interferometry,

changes on OES signal amplitude allows to

identify interfaces between GaAs and GaAlAs

LASER DIODE, PHOTODETECTORS, LASER MIRRORS…


Sandwich (MQW, Braggs,..) features LEM-CT

III-V,

InP

200

nmIn

GaA

s10

3 nm

InP

1060

nm

Qua

tInG

aAsP

75 n

mIn

P: p

473

nm

Qua

tSC

H +

MqW

s21

7 nm

(SC

H :

55 n

m In

GaA

sP2

MqW

: InG

aAsP

3)

InP

: n 1

040

nm

Bra

gg m

irror

s

300 s

Applications : Deep etching of III.V materials GaAs, InP, ternary (InGAs, AlGaAs,...), quaternary (InGaAsP), nitride (GaN, AlGaN, ...)

Applications : Etching of III-V semiconductors on GaAs and InP sustrates: ternary, quaternary, nitrides (AlGaAs/GaAs, InGaAsP/InP, InGaAlAs/InP, GaN, ...)


SOI, Metal etching, Bosch process using LEM-CT

SOI, Metal etching, Semiconductors, dielectrics and oxide, Bosch process, …

� Metal etching

� SOI, III-V’s stacks

Titanium etch SiO2

substrate

� Bosch Process (Deposition/Etch Cycle)

D E D E D E D E


OES ApplicationsOES ApplicationsOES ApplicationsOES Applications

Process time (sec)

Pla

sma

Inte

nse

(a.u

.)

Before During After

Endpoint

Photomask etching


Advanced Process Control

End point as Standard Monitoring

� Increase yield and throughput

� Process stability

� Run to Run control

� Misprocessing

Limitation of End point Monitoring

� Low Open area / High device density

� Selective chemistry

� Tool

� Magnetic field

� …

Advanced Equipment Control

Health monitoring introduction

� Process characterization

� Chamber characterization

� EPD Complement or substitute

ENDPOINT

Vacuum leakChemistry ratio

Chamber conditioningChamber Drift before Wet Clean

Bad LithographyMicro-arcing

…

ENDPOINT

Vacuum leakChemistry ratio

Chamber conditioningChamber Drift before Wet Clean

Bad LithographyMicro-arcing

…

Typical CCD Spectrum

Depending on some combination

AEC/APC

Chamber health Monitoring:• Chamber cleaning• Chamber conditioning to avoid first wafer effect• Chamber matching and troubleshooting• Chamber gas leak detection or gas purity control• Preventive maintenance (Wet Clean )• Unexpected events (arcing , …)


Recipe designer : search ruptures

Rupture

Rupture

STEP 2

Identification of the rupture point using the approximation of 2 straight lines

STEP 1

Automatic wavelengths

classification (pattern)

STEP 3

The Endpoint recipe is built using rupture intensity threshold. Export it to Sigma-P

Example of Recipe designer setting to develop an endpoint recipe

Rupture intensity

Upward rupture: Averaged

wavelengths

Wavelengths classification

Threshold

APC


OES Engineering flow

new proprietary mathematical algorithms:• Slope change using kinetic trend fitting• Periodic component filtering based on wavelet theory• Application on the fly at each new OES spectrum acquisition• Statistic study of rupture presence probability.

Spectra recipe

APC


Endpoint detection

Layer1

Layer2

Substrate

Raw data

Signal variation enhancement by special Algorithm

Upward Curves

Downward Curves

EndpointRemove frequentbackground

Process target :Etch Stop at Interfacebetween Layer 1 & Layer 2

Real time dataprocessing for EPD :

- Signal Acquisition- Real time data Treatment- Algorithm to enhance

production variation- EPD condition monitoring

Start Variation

Process time (sec)

APC


Health Monitoring : chamber management

Acceptable

Chamber drift

Ratio evolution

Stop Chamber and

operate a Wet

Clean

For each wavelengths within a range, Ratio

between spectra reference & current

spectra

AEC


Conclusion

� HORIBA Introduces New OES product: EV-140 C that has UV enhanced Spectrograph and powerful software platform for total solutions of Process engineering and production.

� Unique Rupture algorithm is designed and developed for Critical endpoint detections.

� Recipe Designer is the tool dedicated to Process Engineers to develop and optimize quickly and quite automatically their processes.

� It includes FDC, health monitoring capabilities to reduce tools downtime, optimise quality and secure wafers production

� Horiba introduces New Interferometric product: DigiLEM-H to have a complete proposal depending on applications:

� LEM-CT – Laser camera at 670 nm

� LEM-CT – Laser camera at 905 nm

� DigiLEM-H–Tilt head with light sources to cover 300 – 700 nm

� Pattern recognition & Powerful algorithms to manage a broad range of films

� One unique software, whatever the sensor. User friendly operation.

� Ability to interface most of the current etchers from any vendor

� Database, Statistics & Multi-run-viewer are dedicated to process engineer and production to be sure that processes stay under control.


� Visit our web sitehttp://www.horiba.com/us/en/semiconductor/products/product-lines/semiconductor-manufacturing-process-monitor/

� Leaflet, presentations, oral presentations

http://horiba-endpoint-semi-mems-fpd.com/

real time etching end point monitors (oes & interferometer...

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