Optical Emission Spectroscopy Etching End-point Monitor

Optical Emission Spectroscopy Etching End-point Monitor EV-140C

Overview

This is an emission analysis type end-point monitor intended for end-point detection or plasma condition control in the plasma-based semiconductor thin-film process. The newly-developed Rapture Intensity algorithm allows accurate end-point detection by capturing faint signal changes. The ability of capturing subtle changes in emission has significantly improved the sensitivity. The enhanced noise immunity ensures highly stable operation in hostile environments of round-the-clock manufacturing lines.

Features

  • Bright grating with opening ratio of F/2
    A bright optical system is achieved by the use of a large, aberration-correcting concave grating of 70 mm in diameter manufactured by HORIBA Jobin Yvon. The light-gathering ability of the concave grating itself enables the construction of a simple optical system that is brighter than Czerny-Turner spectroscopes and that can minimize the reflection loss caused by mirrors and other reflective surfaces.
  • Back-illuminated CCD line sensor offering high sensitivity and high resolution of 2,048 channels
    A back-illuminated CCD achieves high quantum efficiency, ensuring stable spectroscopy in the broad spectrum from UV to visible regions. The highly sensitive measurement possible in the UV region, in particular, enables end-point detection in the wavelength range which is less affected by interference.
  • Sigma-P software for advanced process control
    This software executes a variety of steps required for process control, from the analysis of plasma behavior to the creation of databases of measured data and remote control of manufacturing equipment.
    The programmable structure of the measurement recipe enables setting of multiple detection conditions and sequential processing. This allows the monitor to be used not only for end-point applications but also for comprehensive plasma condition monitoring.
    Sigma-P software for advanced process control
    Recipe setting example
    This is an advanced setting which warns of abnormal plasma condition as well as conducting end-point measurement using the ratio between two wavelengths.
  • Full reprocessing function
    Once spectroscopy data is obtained, simulation for recipe optimization or end-point detection can be repeated as desired by applying new recipe conditions.
    A library used to identify the emission species in plasma is included as standard.
    Spectroscopy data can be converted into a time course graph, or can be displayed freely on the screen using screen layout, operation waveforms, and comparative calculation waveforms against reference data, and other information.
    Full reprocessing function
  • Auto Pattern software for the analysis of time course patterns
    It is a daunting challenge to find minute pattern changes from an enormous amount of spectrum data with noise. Auto Pattern automatically finds characteristic pattern changes to determine the optimum end-point wavelength.
  • Strong end-point algorithms
    End-points can be accurately detected by using the user-specified wavelength-to-wavelength calculation waveform and filtering. The newly-developed Rapture Intensity algorithm allows constant monitoring of the changes in the intersecting angle between the two straight lines which approximate the two specified sections. This ensures that points of change are differentiated appropriately from noise without delay, and that extremely small signal changes such as end-points with small opening areas, are accurately detected.
    Example of weak signal waveform reprocessing
    Example of weak signal waveform reprocessing
    Etching monitoring over a small opening area (<0.2%).
    After a frequency filter processes noise from the original signal, the differential signal (pink line) of the ratio (black line) of (rise (A+B+C)/decrease (D+E+F) curve) leads to accurate detection of the end-point.
  • Recipe Designer, a recipe generation tool automatically synchronised with analysis results (optional software)
    Recipe Designer is an extended version of the Auto Pattern analysis tool. It allows the user to generate an optimum Rapture Intensity algorithm simply by following on-screen instructions for analysis and simulation. The algorithm can easily be built into the real recipe. This can greatly lighten the load of recipe generation for end-points of weak and complicated emission species or end-points which cannot be detected due to changes in process conditions, or similar cases.
    Example of Recipe Designer setting
    Example of Recipe Designer setting
    STEP1: Automatic extraction of the pattern of wavelength changes
    STEP2: Identification of the point of change using the approximation of two straight lines
    STEP3: The EDP simulation conducted by Rapture Intensity and the completed algorithm can be exported and built into Sigma-P.
  • Advanced statistical processing: Feedback to recipes
    The statistical process editor is able to analyze the log data from many different perspectives, helping to improve abnormality analysis and yield rates. The results of the analysis can be fed back to measurements.

 

Manufactured by HORIBA

Specifications

Sensor unit

Optical unit

Wavelength range

200 - 800 nm

Optical resolution

<2.0 nm @ =200 - 500 nm
<2.5 nm @ =500 - 700 nm
(FWHM theoretical resolution)

Optical design

Design

Aberration corrected Flat field concave grating

Focal length

140 mm

2nd order filter

Built-In

Detector

CCD type

Back thinned linear CCD image sensor

Pixel number

2048 × 64

A/D resolution

16 bit

Integration time

20 ms - 2.5 s (10 msec step)

Specification

Optical input

Optical fiber

Sensor unit dimensions

137 (W) × 156 (H) × 257 (D) mm
5.4 (W) × 6.1 (H) × 10.1 (D) in

Sensor unit mass

4.0 kg

Connecting chamber number

1 Ch

Power supply

24 V DC ± 10 %

Power consumption

12 VA (Max)

Operating temperature requirements

15 - 35 °C

Ambient temperature

0-50 °C (no condensation)

Operating moisture requirements

<80%RH at 25 °C (no condensation)

Front LCD display

Run status indicator (Sensor err /Controller err)

Cooling fan

DC fan

IN/OUT

◎ for Output signal with measurement curve link

Output port number

2 ch

Output range

0 - 5 V DC

◎ for PIO remote protocol

Digital output

PIO / (DI = 8 bit/ DO = 8 bit)

PIO remote protocol connector

Dsub25S
(PIO port, Analog output port)

Controller interface

Ethernet × 1 port

Controller unit

Unit dimension

197 (W) × 148 (H) × 250 (D) mm
7.8 (W) × 5.8 (H) × 9.8 (D) in

OS

WindowsXP embeded (English version)

CPU

Celeron 1.3 GHz

Main memory

1 GB

HDD

80 GB

Interface

Ethernet × 2, RS232C × 2

Power supply

90 - 264 V AC, 50/60 ± 3 Hz

Remote protocol capability

Communication

PIO/RS232C serial
＊Designing capability for LAN communication

Certification

Standards

CE/FCC

Accessory

Optical fiber

Specification

Quartz fiber

Fiber grade

VIS or UV

Fiber length

2 m

Option

DC power supply unit

Power supply

90-264 V AC 50/60 ±3 Hz

DC power supply spec

24 V DC, 2 A output

Chamber adapter

Adapter

Condenser lens unit

PC accessory

PC accessory

LCD monitor/Key board / mouse

PC battery option

UPS

UPS option for controller PC