The fully automated industrial WLI-AFM system
Park NX-Hybrid WLI is the first-ever AFM with built-in WLI profilometry for semiconductor and related manufacturing quality assurance, process control for semiconductor front-end, back-end up to advanced packaging, and R&D metrology. It is for those that require high throughput measurements over a large area that can zoom down to nanometer-scale regions with sub-nano resolution and ultra-high accuracy.
The two best complementary technologies for semiconductor metrology
- WLI: White light interferometry is an optical technique that can image a very wide area, very fast, producing high throughput measurements.
- AFM: Atomic force microscopy is a scanning probe technique that delivers the highest nanoscale resolution measurements even for transparent materials.
| Measurement Area | Speed | Lateral Resolution | Vertical Resolution | Accuracy | |
|---|---|---|---|---|---|
| WLI | Large | High | Low | High | Low |
| AFM | Small | Low | High | Very High | High |
| WLI | AFM | |
|---|---|---|
| Measurement Area | Large | Small |
| Speed | High | Low |
| Lateral Resolution | Low | High |
| Vertical Resolution | High | Very High |
| Accuracy | Low | High |
WLI and AFM complement each other in field of view, resolution, and speed
WLI applications requiring much higher resolution and accuracy beyond WLI capability
- Advanced CMP metrology and monitoring
- Advanced packaging
- Hot-spot and defect detection on full reticle die
- Wafer level metrology
AFM applications requiring much higher throughput over much larger areas
- In-line Wafer Metrology
- Long Range Profiling for CMP Characterization
- Sub-Angstrom Surface Roughness Control
- Wafer Inspection and Analysis
NX-Hybrid WLI features
Park WLI System
- Park WLI supports WLI and PSI modes (PSI mode is supported with Motorized Filter Changer)
- Available objectives lens magnification: 2.5X, 10X, 20X, 50X, 100X
- Two objective lenses can be automatically replaced by Motorized Linear Lens Changer
WLI Optical Interferometry
- The height of sample surface at each pixel can be calculated from the light intensity variation due to interference while scanning the height of Mirau objective lens
- White light interferometry (WLI) and phase shifting interferometry (PSI) are two popular techniques for surface characterization
NX-Hybrid WLI Applications
Hotspot Detection and Review
Fast survey of hotspots and automated review of hotspot defects
- Hotspots of a patterned structure can be detected by comparing images of reference and target sample areas
- High speed “hotspot detection” by WLI enables fast localization for defect sites for high resolution AFM review
High productivity and powerful features for inline wafer-fab metrology
Hot Spot Detection and Review by WLI and AFM
The new 300mm bare wafer ADR provides a fully automated defect review process from transfer and alignment of defect maps to the survey and zoom-in scan imaging of defects that uses a unique remapping process that does not require any reference marker on a sample wafer. Unlike SEM which leaves square-shaped destructive irradiation marks on defect sites after its run, . the AFM-based defect review enables non-destructive 3D imaging of defects as small as a few nanometers. The linkage between a defect inspection tool and the AFM is carried out by advanced coordinate translation with enhanced vision technique. Since it is fully automated, it does not require any separate steps to calibrate the stage of the targeted defect inspection system, increasing throughput by up to 1,000%.
Read More related application
Automatic Transfer and Alignment of Defect Maps with Enhanced Vision
By utilizing Park's proprietary coordinate translation technique, the new Park ADR AFM can accurately transfer the defect maps obtained from a laser-scattering defect inspection tool to a 300mm Park AFM system. This technology does not require any separate step to calibrate the stage of the targeted defect inspection system and allows full automation for high throughput defect imaging.
Automated Search & Zoom-in Scan
The defects are imaged in two steps;(1) a survey imaging, either by AFM or enhanced optical vision, to refine the defect location, then (2) a zoom-in AFM scan to obtain a detailed image of the defect, presenting automatic analysis of the defect type and the subsequent defect dimensions. .
Park NX-Hybid WLI Specifications
System
Specification
Motorized XY stage
200mm : travels up to 275 mm × 200 mm, 0.05 µm resolution
300mm : travels up to 400 mm × 300 mm, 0.5 µm resolution, 1 µm repeatability
Motorized Z stage
25 mm Z travel distance,
0.08 µm resolution, < 1 µm repeatability
Motorized Focus Stage
9 mm Z travel distance for on-axis optics
Sample Thickness Allowance
up to 20 mm
Full scan range Z run-out
< 2 nm, repeatability < 1nm
COGNEX Pattern Recognition
pattern align resolution of 1/4 pixel
Scanner Performances
XY Scanner
100 µm × 100 µm (Large mode)
50 µm × 50 µm (Medium mode)
10 µm × 10 µm (Small mode)
Single-module flexure XY scanner with closed-loop control
XY Scanner Resolution
0.15 nm (Large mode)
Z Scanner Range
15 µm (Large mode)
2 µm (Small mode)
Z Scanner Resolution
0.016 nm (Large mode)
0.002 nm (Small mode)
Z Scanner Detector Noise
0.02 nm @ 1kHz
AFM and XY Stage
Control Electronics
ADC
18 channels
4 high-speed ADC channels
24-bit ADCs for X,Y and Z scanner position sensor
DAC
17 channels
2 high-speed DAC channels
20-bit DACs for X,Y and Z scanner positioning
Compliances
CE
SEMI Standard S2/S8
Vibration, Acoustic Noise, and ESD Performances
Floor Vibration
< 0.5 µm/s (10 Hz to 200 Hz w/ Active Vibration Isolation System)
Acoustic Noise
>20 dB attenuation w/ Acoustic Enclosure
Facility Requirements
Room Temperature (Stand By)
10 °C ~ 40 °C
Room Temperature (Operating)
18 °C ~ 24 °C
Humidity
30% to 60% (not condensing)
Floor Vibration Level
VC-D (6µm/sec)
Acoustic Noise
Below 65 dB
Pneumatics
Vacuum : -80 kPa
CDA (or N2): 0.7 MPa
Power Supply Rating
208V - 240 V, single phase, 15 A (max)
Total Power Consumption
2 KW (typical)
Ground Resistance
Below 100 ohms
Options
Long Range Sliding Stage
• 200mm : 10 mm
• 300mm : 25 mm (optional 10 mm or 50 mm)
Automatic Tip Exchange (ATX)
Automatic Tip Exchange performs fully automated tip exchanges in order to seamlessly continue automated measurement routines. It automatically calibrates cantilever location and optimizes measurement settings based on measurements of a reference pattern. Our novel magnetic approach to the tip exchange yields a 99% success rate, higher than the traditional vacuum techniques.
Automatic Wafer Handler (EFEM or FOUP)
The XE-3DM can be further customized by adding an automatic wafer handler (EFEM or FOUP or other). The high-precision, nondestructive wafer handler robot arm fully ensures XE-3DM users to receive fast and reliable wafer measurement automation.
Ionization System
Ionization system effectively removes electrostatic charges. It ionizes the charged objects and is very reliable since the system always generates and maintains an ideal balance of positive and negative ions without causing any contamination to the surrounding area. It also reduces the accidental electrostatic built-in charge that may occur during sample handling.
Dimensions & Weight
200 mm System
2732 mm(w) × 1100 mm(d) x 2400 mm(h)
w/ EFEM, 2110 kg approx. (incl. Control Cabinet)
Ceiling Height
2500 mm or more
Operator Working Space
3300 mm (w) x 1950 mm (d), Minimum
300 mm System
3486 mm(w) × 1450 mm(d) x 2400 mm(h)
w/ EFEM, 2950 kg approx. (incl. Control Cabinet)
Ceiling Height
2500 mm or more
Operator Working Space
4770 mm (w) x 3050 mm (d), Minimum
NX-Hybrid WLI Specification
Mode
WLI, PSI
Scan Velocity
12 μm/sec
Lateral Resolution
0.38 μm
Motorized Turret
2 lens
Maximum Scan Range
WLI 28 μm, PSI 100 nm (0 ~ 5 μm)
Vertical Resolution
0.1 nm
Repeatability
0.1% @ 1σ
Productivity meets Accuracy
Automatic Tip Exchange (ATX)
The ATX automatically locates tips by pattern recognition and uses a novel magnetic approach to disengage a used tip and pick up a new tip, with an incredible 99.9% success rate. The laser spot is then automatically optimized along the X- and Y-axis by motorized positioning knobs.
Ionization System for a more stable scanning environment
Our innovative ionization system quickly and effectively removes electrostatic charges in your sample's environment. Since the system always generates and maintains the ideal balance of positive and negative ions, it can create an extremely stable charge environment with little contamination of the surrounding area and minimal risk of accidental electrostatic charge during sample handling.
Automatic Wafer Handler (EFEM or FOUP)
The NX-WAFER can be configured for various automatic wafer handlers (EFEM or FOUP or other). The high-precision, nondestructive wafer handler robot arm fully ensures users always get fast and reliable wafer measurements.
