Application of the Atomic Force Microscope to Integrated Circuit Reliability and Failure Analysis

Abstract This paper presents a method of using a conductive atomic force microscope (C-AFM) to characterize a submicron metal fuse that has been blown open inadequately by laser. In order to obtain a proper I-V curve measured using the C-AFM without affecting the incompletely opened fuse, the paper proposes a method of preserving the fuse by coating its surface with spin-on glass. The paper explains how differences in laser cutting machines resulted in the high failure repair rate of customer product despite equivalent energy and spot size settings. Analysis of the fuse bank circuitry on wafers helped to find the critical physical differences between a fully blown and a poorly blown fuse. By overcoming difficulties in preserving the blown fuse failure sites for C-AFM measurement, laser settings could be easily optimized to ensure proper fuse opening.

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A Study of the Photoelectric Effect Caused by a Laser Beam Used in a Beam Bounce Technique in a C-AFM System

ISTFA 2008: Conference Proceedings from the 34th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2008p0256 ◽

2008 ◽

Author(s):

Hung-Sung Lin ◽

Mong-Sheng Wu

Keyword(s):

Laser Beam ◽

Failure Analysis ◽

Atomic Force Microscope ◽

Photoelectric Effect ◽

Scanning Probe ◽

Nanometer Scale ◽

Electrical Characteristics ◽

Atomic Force ◽

Probe Microscope ◽

Probe Head

Abstract The use of a scanning probe microscope (SPM), such as a conductive atomic force microscope (C-AFM) has been widely reported as a method of failure analysis in nanometer scale science and technology [1-6]. A beam bounce technique is usually used to enable the probe head to measure extremely small movements of the cantilever as it is moved across the surface of the sample. However, the laser beam used for a beam bounce also gives rise to the photoelectric effect while we are measuring the electrical characteristics of a device, such as a pn junction. In this paper, the photocurrent for a device caused by photon illumination was quantitatively evaluated. In addition, this paper also presents an example of an application of the C-AFM as a tool for the failure analysis of trap defects by taking advantage of the photoelectric effect.

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Sample Preparation of Aluminum Bridge Test Vehicles for Tem In-Situ Crystallographic Studies of Electromigration

MRS Proceedings ◽

10.1557/proc-115-173 ◽

1987 ◽

Vol 115 ◽

Author(s):

W. E. Rhoden ◽

J. V. Maskowitz ◽

D. R. Kitchen ◽

R. E. Omlor ◽

P. F. Lloyd

Keyword(s):

High Temperature ◽

Sample Preparation ◽

Integrated Circuit ◽

Circuit Reliability ◽

Test Vehicle ◽

Aluminum Films ◽

Current Densities ◽

Integrated Circuit Reliability ◽

A Current

IntroductionElectromigration in aluminum films has been identified as an increasing concern for integrated circuit reliability. Electromigration is the mass transport of atoms in a conductor under a current stress. Electromigration occurs in conductors experiencing current densities greater than 105 A/cm2 and is accelerated by high temperature. The damage to aluminum films manifests itself in the formation of voids, hillocks and whiskers along the conductor. This paper presents a test vehicle preparation procedure which can be used to investigate electromigration.

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