Critical Dimension (CD) Atomic Force Microscopy (AFM) is a primary means to measure the geometric shapes of walls and trenches on the nanometer scale in laboratories supporting the electronic industry. However, with CD-AFM, it is difficult to predict the measurement bias arising from the compliance of the AFM probe. The issue becomes particularly important when nanometer uncertainties are required and CD tips are used as high resolution probes. In order to estimate the probe deflections due to surface intermittent contact and the resulting dimensional biases and uncertainties, we have developed finite element models for simulating dynamic behavior of AFM cantilevers with a CD tip attached. Probe tip and cantilever beam responses to intermittent contact between the probe tip and sample surface are computed using the finite element method. Using the commercially available software system, Simulia*, intermittent contacts with a wall and a horizontal surface are computed and modeled, respectively. The responses of the probe to interaction forces between the sample surface and the probe tip are shown in both time and frequency domains.
Proceedings Title: Scanning 2008
Conference Dates: April 15-17, 2008
Conference Location: Gaithersburg, MD
Pub Type: Conferences
Atomic force, Cantilever, Critical Dimension, Compliance, Microscopy, Nanometrology, Probe modeling, Scanned probe