Precision Ion Milling of Layered, Multi-Element TEM Specimens with High Specimen Preparation Spatial Resolution

1991 ◽  
Vol 254 ◽  
Author(s):  
Ron Anderson ◽  
John Benedict
Keyword(s):  
Composite Material ◽  
Failure Analysis ◽  
Spatial Resolution ◽  
Ceramic Composite ◽  
Semiconductor Industry ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Tem Analysis ◽  
Ceramic Composite Material ◽  
Resolution Requirements

It is now a requirement in the semiconductor industry to prepare TEM specimens of pre-specified regions with a specimen preparation resolution exceeding 100nm. In other words, given the coordinates x, y, z of the location desired for TEM analysis, the TEM specimen preparation procedure must yield a thin TEM specimen containing the point x, y, z plus or minus 100nm. Preparation of failure analysis specimens in other fields of endeavor, such as: metallurgical, ceramic, composite material laboratories etc., have specimen preparation spatial resolution requirements below one micron in some cases with the likelihood that greater precision will be required in the future.

Comparison of Precision XTEM Specimen Preparation Techniques for Semiconductor Failure Analysis

1997 ◽  
Vol 3 (S2) ◽  
pp. 357-358
Author(s):  
C. Amy Hunt
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Mechanical Polishing ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Tem Analysis ◽  
The Past ◽  
Preparation Techniques

The demand for TEM analysis in semiconductor failure analysis is rising sharply due to the shrinking size of devices. A well-prepared sample is a necessity for getting meaningful results. In the past decades, a significant amount of effort has been invested in improving sample preparation techniques for TEM specimens, especially precision cross-sectioning techniques. The most common methods of preparation are mechanical dimpling & ion milling, focused ion beam milling (FIBXTEM), and wedge mechanical polishing. Each precision XTEM technique has important advantages and limitations that must be considered for each sample.The concept for both dimpling & ion milling and wedge specimen preparation techniques is similar. Both techniques utilize mechanical polishing to remove the majority of the unwanted material, followed by ion milling to assist in final polishing or cleaning. Dimpling & ion milling produces the highest quality samples and is a relatively easy technique to master.

Recent Developments in the use of the Tripod Polisher for TEM Specimen Preparation

1991 ◽  
Vol 254 ◽  
Author(s):  
John Benedict ◽  
Ron Anderson ◽  
Stanley J. Klepeis
Keyword(s):  
Cross Sections ◽  
Colloidal Silica ◽  
Mechanical Stability ◽  
Semiconductor Industry ◽  
Polished Surface ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Thin Specimen ◽  
Tem Analysis ◽  
Area Of Interest

AbstractCross sections of material specimens for TEM analysis must be produced in the shortest time possible, contain few, if any, artifacts and have a large area available for analysis. The analyst must also be able to prepare these cross sections from specified areas of complex, heterogeneous structures on a routine, reproducible basis to meet the growing needs of the semiconductor industry for TEM analysis. The specimen preparation spatial resolution required for preparing precision cross sections is substantially less than one micron. Cross sections meeting these requirements can be prepared by mounting a specimen to the Tripod Polisher and mechanically polishing on one side of the specimen, using a sequence of progressively finer grit diamond lapping films, until the area of interest is reached. This polished surface is then very briefly polished on a cloth wheel with colloidal silica to attain the final polish on that side. The specimen is then flipped over on the Tripod Polisher and polished from the other side, using same sequence of diamond lapping films to reach the predefined area of interest. The Tripod Polisher is set at a slight angle, to produce a tapered, wedge-shaped specimen, which has the area of interest at the thinnest edge of the taper. The specimen is polished with the diamond lapping films and the colloidal silica until it is 1000 Angstroms or less in thickness. The specimen is removed from the polisher and mounted on a 2 × 1mm slotted grid with M-Bond 610 epoxy. After the epoxy is cured the specimen can be taken directly to the microscope for analysis. The need for ion milling has been eliminated or reduced to a few minutes in most of our work because of the thinness of the final specimen. The total specimen preparation time is between 2.5 and 4 hours, depending on the specimen and the size of the specified area. The area available for analysis ranges from 0.5mm up to the full size of the mounting grid opening. The wedge shape of the specimen provides the mechanical stability needed for a long thin specimen.

Specific site device failure analysis: A case history

1992 ◽  
Vol 50 (2) ◽  
pp. 1390-1391
Author(s):  
Ron Anderson ◽  
Joseph Wall ◽  
Stanley Klepeis
Keyword(s):  
Failure Analysis ◽  
Spatial Resolution ◽  
Case History ◽  
Integrated Circuit ◽  
Specimen Preparation ◽  
Tem Analysis ◽  
Device Failure ◽  
History Of ◽  
Analysis Application ◽  
Electrical Diagnostics

Failure analysis application of analytical TEM analysis was handicapped in the past by the difficulty associated with specimen preparation of specific devices in complicated integrated circuit arrays. We have published several papers detailing methods for preparing TEM specimens with high specimen preparation spatial resolution in periods of about two to four hours. This paper offers a case history of a TEM failure analysis that combines high spatial resolution specimen preparation and the utilization of chemical junction delineation techniques.The device failure came to light in a chip tester prior to shipment. Tester electrical diagnostics identified a particular cell within a large array as defective. The fail's electrical signature further narrowed-down the potential candidates to a small number of devices within the cell. The chip was examined in transmission in an IR microscope. Anomalous IR contrast was observed in the emitter of one bipolar device in the suspect region (Fig. 1). A series of conventional light-optical photographs, with increasing magnification, were taken to define the failure location. Using the light-optical photos as a guide, the failed emitter was bracketed with laser craters. The specimen preparation polishing operation used the laser craters to achieve a plane-of-polish through the suspect emitter.

scholarly journals Site-Specific Cross-sectioning of IC Devices for Failure Analysis by SEM/TEM: Specimen Preparation Challenge and Approach

1994 ◽  
Vol 2 (4) ◽  
pp. 9-10
Author(s):  
Farhad Shaapur
Keyword(s):  
Failure Analysis ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Specimen Preparation ◽  
High Magnification ◽  
Device Structure ◽  
Tem Analysis ◽  
Site Specific ◽  
Additional Requirement ◽  
Microelectronic Devices

Cross-sectioning of microelectronic devices for the purpose of construction or failure analysis by SEM and/or TEM has always been considered a major challenge. The ever increasing complexity and shrinking dimensions of these devices have pushed the art and science of the related specimen preparation beyond their conventional limits. The need for SEM failure analysis of sub-micron elements of a failed device requires the capability of cross-sectioning the sample with a high spatial-resolution within a specific transverse piane. An image of the device structure obtained at sufficiently high magnification from the above specimen generally reveals the defect(s) responsible for the failure. If the imaging resolution and contrast offered by an SEM prove to be inadequate for the above purpose, device structure will be inspected via TEM. Analysis of such device by TEM imposes the additional requirement of back-thinning the above specimen to electron transparency at the site of failure.

A High Resolution TEM Specimen Thinning System

1991 ◽  
Vol 254 ◽  
Author(s):  
R. Clampitt ◽  
G. G. Ross ◽  
M. Phelan ◽  
S. A. Davies
Keyword(s):  
High Resolution ◽  
Failure Analysis ◽  
Spatial Resolution ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Tem Analysis ◽  
Commercial System ◽  
High Resolution Tem

AbstractImprovements in specimen preparation for TEM analysis are being constantly sought, particularly in the study of microelectronics' materials and in failure analysis of devices. We describe here a compact commercial system capable of thinning (milling) selected regions of a specimen by means of a scanned focused ion beam of sub-micron spatial resolution.

A procedure for cross-sectioning materials for TEM analysis without ion milling

1990 ◽  
Vol 48 (4) ◽  
pp. 742-743
Author(s):  
J.P. Benedict ◽  
Ron Anderson ◽  
S. J. Klepeis
Keyword(s):  
Surface Topography ◽  
Milling Time ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Cleaning Operation ◽  
Tem Analysis ◽  
Platinum Silicide ◽  
Surface Alteration ◽  
Polishing Damage ◽  
Tools And Methods

Traditional specimen preparation procedures for non-biological samples, especially cross section preparation procedures, involves subjecting the specimen to ion milling for times ranging from minutes to tens of hours. Long ion milling time produces surface alteration, atomic number and rough-surface topography artifacts, and high temperatures. The introduction of new tools and methods in this laboratory improved our ability to mechanically thin specimens to a point where ion milling time was reduced to one to ten minutes. Very short ion milling times meant that ion milling was more of a cleaning operation than a thinning operation. The preferential thinning and the surface topography that still existed in briefly ion milled samples made the study of interfaces between materials such as platinum silicide and silicon difficult. These two problems can be eliminated by completely eliminating the ion milling step and mechanically polishing the sample to TEM transparency with the procedure outlined in this communication. Previous successful efforts leading to mechanically thinned specimens have shown that problems center on tool tilt control, removal of polishing damage, and specimen cleanliness.

Transmission Electron Microscopy of Semiconductor Based Products

1998 ◽  
Vol 523 ◽  
Author(s):  
John Mardinly ◽  
David W. Susnitzky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Size Reduction ◽  
Specimen Preparation ◽  
Specimen Thickness ◽  
Ion Milling ◽  
Feature Size ◽  
Transmission Electron

AbstractThe demand for increasingly higher performance semiconductor products has stimulated the semiconductor industry to respond by producing devices with increasingly complex circuitry, more transistors in less space, more layers of metal, dielectric and interconnects, more interfaces, and a manufacturing process with nearly 1,000 steps. As all device features are shrunk in the quest for higher performance, the role of Transmission Electron Microscopy as a characterization tool takes on a continually increasing importance over older, lower-resolution characterization tools, such as SEM. The Ångstrom scale imaging resolution and nanometer scale chemical analysis and diffraction resolution provided by modem TEM's are particularly well suited for solving materials problems encountered during research, development, production engineering, reliability testing, and failure analysis. A critical enabling technology for the application of TEM to semiconductor based products as the feature size shrinks below a quarter micron is advances in specimen preparation. The traditional 1,000Å thick specimen will be unsatisfactory in a growing number of applications. It can be shown using a simple geometrical model, that the thickness of TEM specimens must shrink as the square root of the feature size reduction. Moreover, the center-targeting of these specimens must improve so that the centertargeting error shrinks linearly with the feature size reduction. To meet these challenges, control of the specimen preparation process will require a new generation of polishing and ion milling tools that make use of high resolution imaging to control the ion milling process. In addition, as the TEM specimen thickness shrinks, the thickness of surface amorphization produced must also be reduced. Gallium focused ion beam systems can produce hundreds of Ångstroms of amorphised surface silicon, an amount which can consume an entire thin specimen. This limitation to FIB milling requires a method of removal of amorphised material that leaves no artifact in the remaining material.

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