3D Imaging and Metrology for Data Storage Applications

By AZoM

Table of Contents

Zeta-20 3D Metrology Microscope

Advanced data storage design demands extreme requirements on hard disks and other components (Fig. 1). The Zeta-20 3D Imaging and Metrology Microscope measures the parameters that ensure high performance of disk drives including edge chamfer angle, roughness and width, disk roll-off, sidewall defects, lube pickup and step heights on the read/write head, defects and roughness on almost any surface. Measurements are both rapid and convenient ensuring high precision for production or failure analysis.

Figure 1. Image of a hard disk.

Measurements Using Zeta-20 Metrology Microscope

The various measurements that can be performed with the Zeta-20 can be classified into two categories

• Disk Edge Characterization.
• Read/Write Head Characterization.

Disk Edge Characterization

Chamfer Width and Angle

A motorized tilt stage aligns the disk edge accurately to measure the chamfer width and angle with respect to the data zone, as well as the roughness of each surface (Fig. 2). Sequences offer automated measurements at multiple locations.

Figure 2. Measurement of the chamfer width and angle with respect to the data zone, as well as the surface roughness.

Disk Roll-off

Disk roll-off is highly important since present fly heights approach 2 nm and data is written as near to the disk edge as possible. This 6.5-nm "ski jump" is potentially catastrophic.

Figure 3. Disk roll-off measurement.

Failure Analysis

Failure analysis of defects on the upper surface or the sidewall takes only a minute. It is possible to obtain true color images and height analysis on both glass (Fig. 4, left) and metal (Fig. 4, right) substrates using the Zeta-20.

Figure 4. True color images and height analysis on glass (left) and metal (right) substrates.

Magnetic Marking

It is possible to image magnetic marking and find the defect to be scanned (Fig. 5).

Figure 5. Imaging of magnetic marking for defect identification.

Read/Write Head Characterization

Zeta 3D software has the capability to sense lube pickup and calculate areas based on height or color, converting a commonly manual inspection into a consistent and quantitative analysis (Fig. 6).

Figure 6. Automated analysis of lube pickup and identification of separate areas based on height or color.

The Zeta-20 scans large areas with high Z resolution. This read/write head has steps of 0.26 μm and 1.72 μm and a scan area of 1896 x 1422 μm (Fig. 7).

Figure 7. Zeta-20 measurement of a sample read/write head.

The Zeta-20 Data Storage Package

The Zeta-20 3D Metrology Microscope offers a large number of benefits that include the following:

• Customized applications for data storage measurements.
  • Chamfer width, angle, roughness.
  • Full read-write head 3D profile.
  • Lube pickup.
• Motorized chucks for standard disk sizes.
• Submicron resolution over a scan range greater than 1 mm.
• Ability to measure very high-reflectivity and very low-reflectivity surfaces.
• Ability to determine very high-roughness and very low-roughness surfaces (with Nomarski DIC option).
• True color imaging.

Zeta 3D Software analyzes 2D or 3D images for general surface characterization:

• Step height.
• Surface roughness.
• Feature size, diameter, area and volume.
• 3D surface visualization.

Figure 8. Zeta-20 system series.

About Zeta Instruments

Zeta Instruments is a leading provider of precision microstructure and surface measurement systems that enable manufacturers of green-technology and bio-medical products to substantially improve yields and quality control. Zeta advanced metrology solutions provide direct benefit to the production of high-brightness LEDs, solar cells, micro-fluidics/bio-technology and magnetic storage media. The patented Z-Dot™ technology enables manufacturers to quickly and accurately perform 3D measurement of the micron-scale features of these applications, positioning Zeta as a strategic supplier to these high-growth industries.

Metrology solutions from Zeta Instruments are ideally suited to address the measurement challenges confronted by these industries:

• LED.
• Biotechnology.
• Solar.
• Data storage.

This information has been sourced, reviewed and adapted from materials provided by Zeta Instruments.

For more information on this source, please visit Zeta Instruments.