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Innovative and Versatile System for Measurement of Thickness, Uniformity, Delamination, and Integrity of In Situ Thin Films

详细技术说明

This technology is a new method for measuring the thickness and integrity of thin films (nanometer to micron thickness), primarily those deposited on semiconductor substrates, although it is broadly applicable to many material systems.

*Abstract

This technology is a new method for measuring the thickness and integrity of thin films (nanometer to micron thickness), primarily those deposited on semiconductor substrates, although it is broadly applicable to many material systems. It provides direct measurements, is relatively inexpensive, and can be implemented inline with an existing process. An invaluable series of applications exist for determination of film uniformity, extent of film lamination, and defect detection. 

DESCRIPTION/DETAILS 

This novel technology provides a direct measurement method for assessing the thickness of thin films (nanometer to micron range) of various materials applied to semiconductor substrates. Direct, real-time measurements are provided without sample disruption in a quick, cost-effective manner. Deviations in film thickness, adhesion, and integrity can potentially be assessed, as well. 

Film uniformity is extremely critical in later semiconductor processing stages, where the necessity for selective removal of film sections of variable thicknesses can drastically impact product yield and chip cost. The ability to instantly obtain a full-field visual representation of the uniformity of the film is highly desirable. The ability to assess delamination and the integrity of the interface between chip layers also is critically important, and early detection would substantially mitigate production losses. Similarly, detection of material defects, primarily as residual voids (i.e., the absence of material) in, for example, newly filled via holes would substantially reduce production wastage. 

How It Works 

This technology originated from research into the use of thermoelastic effects to induce thermal effects in a deposited film as a way to measure film thickness. In addition to thermoelastic-based generation of heat (via substrate bending), the technology uses a contact-free, controllable oscillating heat source, such as a heat lamp or other infrared source, underneath the substrate. Oscillating heat is input to the substrate through the heat source (or induced via mechanical excitation through thermoelastic effects). 

In this application, the deposited film absorbs the radiation. The heat first conducts through the substrate, in a characteristic time, and then into and across the film. Thermal response to oscillations of input energy is a function of film thickness; the time required for the signal to conduct through the film is a function of both the thermal properties and thickness of the film. 

Knowledge of thermal properties is required to measure film thickness, and calibration is required for some applications. However, once the system is calibrated for a particular coating's thermal properties, the thickness of the film can be measured directly. Quartz process monitors from the deposition equipment are used for thin film measurements. A full-field camera is synchronized with the input source. 

Why It Is Better 

This technology is relatively inexpensive (compared to ellipsometry) and capable of being implemented inline with the process (unlike profilometry or other destructive measurement techniques). 

This technique requires a short and simple process time (after calibration for a particular material set). Other methods for accurate measurement involve advanced and expensive technology, such as laser ellipsometry. The ability of this technology to be tailored for multiple production-enhancing processes, such as measurement of film uniformity, delamination, and integrity, render it a versatile and highly cost-effective tool for semiconductor processing. 

APPLICATIONS 

• Semiconductor Processing Industry: 
  • Thickness measurements of thin films on transparent substrates 
  • Visual representation of film uniformity (or variability) across a substrate 
  • Determination of the degree of lamination (film adhesion to a substrate) 
  • Detection of defects (e.g., material voids, integrity failures) against known standard 

BENEFITS

• Sample integrity: No destruction or even disturbance of the measured sample. 
• Full-field measurement (no scanning): Instantaneous and continuous readout is provided across the entire film sample. 
• Real-time measurement: Allows real-time measurements of film thickness and uniformity, minimizing production re-runs. 
• Inexpensive: Costs less to implement than alternative methods.

For more information about this technology, please contact the University of Illinois at Urbana-Champaign Office of Technology Management at otm@illinois.edu.

*IP Issue Date

None

*IP Type

Utility

国家

United States

申请号码

7301149

国家/地区

美国