CMP

Chemical Mechanical Planarization (CMP), a key enabler in transistor scaling, is a process used to flatten a wafer surface using a combination of physical and chemical forces. The planarization process is critical for improving device performance and production yield.

For example, wafer planarity is required to isolate features such as copper interconnects and for subsequent processing steps such as photolithography.

Challenges

In the CMP process, maintaining good uniformity across the wafer and wafer-to-wafer is a tough yet critical challenge. In order to ensure consistent uniformity and control the process, continuous, accurate measurements are required.

With the emerging trends such as vertical devices, advanced patterning and new materials, planarity requirements are becoming ever tighter.

As a result, there is a growing need to measure the increasingly complex structure with smaller dimensions with speed and precision. Due to lack of correlation to test structures, some critical transistor levels require measurements of the in-die device structures increasing the complexity of the measurements.

Nova is the industry leader in CMP process control. As an integral part of your production process, Nova’s integrated metrology solutions deliver the highest standards in terms of throughput, reliability and tool-to-tool matching.

Nova’s optimal optical path design and system architecture minimize wafer movements in the metrology process deliver measurement results in short exposure times. This design delivers consistently high accuracy at a fast working pace.

With increasing structure complexity and diminishing geometry sizes, Nova metrology solutions can help you measure a wide range of test structures. Nova’s metrology solutions provide process control for a wide range of CMP processes including:

• Thin film stacks
• Periodic 2D grating structures
• Complex 3D profiles

Highlights

Thin film stacks

The process window, for stop in film CMP processes, is shrinking. This creates an increasing demand for the high precision thickness measurements delivered by metrology systems.

With the industry’s best reflectometry design, Nova’s integrated metrology solution provides the Å level precision needed for thin film stacks used in advanced technology nodes, such as ILD, ONONO and more.

2D periodic grating structures

With the scaling of technology nodes, grating-structures profile measurements are becoming increasingly important. Stop-on-film CMP processes, such as STI and copper interconnect formation levels, require better control of residual film thickness or recess into the underlying structures.

Nova’s scatterometry solutions provide fast and accurate profile measurements of the two dimensional structures with Å level precision and superior tool-to-tool matching.

Complex 3D profiles

CMP process complexity is increasing with industry’s transition to 3D devices, such as FinFET and vertical NAND structures. This trend increases the need for highly accurate measurements and tight process control

Nova brings a powerful, holistic approach to 3D metrology that leverages the company’s advanced metrology products, NovaMARS modeling platform and advanced metrology algorithms. With a top-notch application development team dedicated to delivering effective solutions in short time-to-market, Nova provides fast and accurate metrology solutions for complex 3D devices.