TEM Mill – Model 1051

ION MILLING

Ion milling is used on physical science specimens to reduce thickness to electron transparency. Argon, an inert gas, is ionized and then accelerated toward the specimen surface. By means of momentum transfer, the impinging ions sputter material from the specimen at a controlled rate.

Advanced specimen preparation

For many of today’s advanced materials, analysis by TEM is the best technique for studying material structure and properties. Fischione Model 1051 TEM Mill is an excellent tool for creating the thin, electron transparent specimens needed for TEM imaging and analysis.

Two ion sources

Two TrueFocus ion sources direct controlled- diameter ion beams to the specimen regardless of energy. They can be directed to either one or both specimen surfaces. The ion sources are physically small and require minimal gas but deliver a large range of ion beam energies. When operated in the upper energy range, milling is rapid, even at low angles. When operated at low energy, material is
gradually sputtered from the specimen without inducing artifacts.
The unique design of the TrueFocus ion source maintains a small ion beam diameter, even at a low accelerating voltage, which means the ions are directed only to the specimen and sputtered material is not redeposited from the specimen holder and/or chamber onto the specimen surface.
Ion accelerating voltages are programmable and can be continuously varied from as high as 6.0 keV for rapid milling to as low as 100 eV for final specimen polishing. Ion beam currents can be established from hundreds of nanoamperes to tens of microamperes.
The ion sources are visually aligned from outside the vacuum using a luminescent target.

Automatic gas control

Two mass-flow controllers provide independent and automatic regulation of process gas for the ion sources. The gas control algorithm produces stable ion beams over a wide variety of ion source milling parameters.

Fully integrated dry vacuum system

The integrated vacuum system includes a turbomolecular drag pump backed by a multi- stage diaphragm pump. This oil-free system assures a clean environment for specimen processing.
Because the gas requirements of the TrueFocus ion source are small, the 70 lps turbomolecular drag pump produces an operating system vacuum of approximately 5×10^-4 mbar. The vacuum level is measured with a Pirani gauge and is continuously indicated.

Contamination-free specimen mounting

The specimen holder accommodates double- sided milling to 0° without specimen shadowing. Because the specimen is clamped, there is no possibility of specimen contamination from an adhesive.
A loading station provides a platform for the specimen so it can be easily positioned into the specimen holder. The loading station also activates the specimen clamps.

Chamber

The TEM Mill’s vacuum chamber remains under continuous vacuum during operation. A load lock isolates the high chamber vacuum from ambient during specimen exchange, ensuring optimal vacuum conditions. The small chamber size makes it easy to clean during periodic maintenance.

Quick specimen transfer

The TEM Mill features a vacuum load lock for rapid specimen exchange. Once the specimen holder is placed onto the stage, evacuation of the load lock occurs within a few seconds. A mechanical elevator then moves the stage with the specimen into the milling position.
At the conclusion of the milling process, the specimen holder returns to the load lock but remains under vacuum until vented by the user. Venting takes only a few seconds. The main chamber remains under a continuous vacuum during the specimen exchange.
After venting, the specimen can be rapidly transferred to the TEM, thus reducing contamination from the ambient.

Precise angle adjustment

With the specimen stage fixed in position, the ion sources are tilted to provide the desired milling angle. Tilt angles are continuously adjustable in the range from -10 to +10 ̊.
Ion beam impingement angles are independently adjustable so that the beams can be directed either to the same or opposite specimen surfaces. Different milling angles can be employed for each specimen surface.
When both ion sources are directed to one specimen surface, milling rates are doubled for applications such as back-sided thinning or planar polishing.
Simultaneous milling of both sides avoids redeposition of sputtered material.
Ion milling with low angles of incidence (less than 10 ̊), combined with low-energy ion source operation, minimizes irradiation damage and specimen heating.
Because it facilitates the uniform thinning of dissimilar materials, low-angle milling is highly beneficial when preparing layered or composite materials as well as cross-sectional TEM (XTEM) specimens.

Programmable specimen motion

Specimen rotation is in-plane and continuous throughout 360 ̊°. The TEM Mill is ideally suited to preparing XTEM specimens from heterogeneous or layered materials. Specimen motion control in relation to the ion beam minimizes preferential milling, which can occur when a glue bond line exists in XTEM specimens or when lower atomic number (Z) materials are contained in layered composite specimens.
When milling the bottom surface of the specimen, ion beam sequencing electrically interrupts the flow of ions to the specimen as the specimen holder is rotated through an angle that coincides with the ion beam. This avoids sputtering of the specimen holder.
In addition, the specimen can be rocked in relation to the ion beam so that interfaces or glue lines are never parallel to the direction of the ion beam. Rocking angles ranging from ±40 to ±60 ̊ are typically employed.

Specifications