Thick Films Analysis

Thick Films Analysis is used to measure film thickness and substrates of films from 1 to 150 µm optical thickness, as well as the top surface of films from 0.4 to 150 µm. Thick film measurements work by isolating the interference signals that are created by the multiple material interfaces and require only basic knowledge of the film's index of refraction.

Because they are based on CSI technology, there are several advantages that ZYGO thin film measurement technologies provide compared to other techniques:

• 3D areal surface maps provide context for understanding a process that cannot be observed when film metrology is reduced to a single thickness number.
• Film measurement is performed through-the-lens, which helps to ensure that the region of interest is exactly the region profiled.
• No additional hardware is required for most applications of MBA or thick films measurement.

Thick Films Analysis is available as an option on NewView 9000 and Nexview NX2 profilers, while Advanced Model Based Analysis (MBA) is available as an option exclusively on the Nexview NX2 platform.

Operating Principle

CSI provides non-contact, areal metrology across a wide range of surfaces. When those surfaces are transparent, a portion of the incoming light penetrates the surface, to possibly reflect from the next interface. For materials which are 1 micron and thicker, the Films Analysis package can provide topography data for both the top of the film and the substrate – as well as a precise thickness map of the film itself. For thinner films, down to 0.4 micron, top surface topography only can be measured.

Typical CSI signals for (a) bare surface (no film); (b) thick film (well over 1 µm) with well separated signals from surface and substrate; and (c) sub-micron film with merged surface and substrate signals.

This method of measuring film surfaces is fast, robust, and requires very little a priori knowledge of the sample – only the nominal index of refraction.

The ZYGO Difference

While thick film metrology is not new for CSI instruments, ZYGO’s proprietary technologies power the most capable films metrology package on the market. Consider a challenging case study: a cosmetic, brushed metal surface in a consumer application. To reduce fingerprint visibility and protect the surface, a transparent film is applied. Unlike most semiconductor, MEMS, or optics applications, this film is applied to a relatively rough substrate, reducing signal quality and causing the CSI systems of yesterday to produce noisy, incorrect film topography maps.

With ZYGO’s exclusive films measurement technology, don’t compromise on the rest of your surface measurement needs.

• High speed, non-contact, areal measurements – just like what you’ve come to expect from ZYGO CSI.
• No additional hardware – versions of the Films analysis package can be added to any ZYGO CSI profiler running Mx™ software.
• Consistent measurement technique – measures the same area, with the same imaging system, as a standard measurement. No offsets, guesswork, or trying to find the right spot on the sample.
• Stitching – for larger field of view without compromising lateral resolution, stitched Films measurements provide seamless data.