The IV3/IV4 Ion Milling Systems provide a complete ion milling procedure for TEM sample preparation. The Basic configuration contains two independent and controllable  high-energy - TELETWIN - ion guns. The TELETWIN Ion Gun is composed of two Steigerwald type guns, it provides a high density ion or fast atom beam thus the preparation of samples can be performed during a reasonable time even at low angle bombardment. Its Focused High-energy-Ion Gun version allows even higher milling rate. With the application possibility of the low-energy gun the Combined system can also be used for final polishing.

The third generation of the ion beam milling unit - IV3 - was developed to bombard the specimen surface at a low angle as possible. The next version - IV4 - was constructed for speeding up the thinning process. The equipment was designed by microscopists for high quality sample preparation.

General

The IV3/IV4 Ion Milling Systems provide a complete ion milling procedure for TEM sample preparation. The Basic configuration contains two independent and controllable  high-energy - TELETWIN - ion guns. The TELETWIN Ion Gun is composed of two Steigerwald type guns, it provides a high density ion or fast atom beam thus the preparation of samples can be performed during a reasonable time even at low angle bombardment. Its Focused High-energy-Ion Gun version allows even higher milling rate. With the application possibility of the low-energy gun the Combined system can also be used for final polishing. 

Features

• Multiple ion sources
• High milling rates and final polishing capability in one equipment
• Unique retarding field operation
• Optional reactive ion milling, liquid nitrogen cooling and ion beam slope cutting

Ion sources

The basic configuration of IV3 and IV4 utilizes 2 independent water-cooled high-energy ion sources (operation range: 2 to 10 keV) that are independently controlled. The unique design of the gun mounts makes possible to maneuver the guns in vacuum and set any milling angle from 0 to 90 degrees providing ultimate flexibility and possibility of low-angle shadow-free ion beam thinning. The dual beam modulation system of IV3 and IV4 enables simultaneous thinning of both sample sides at different accelerating voltages.The beam modulation with beams off during 1 of a rotation or the rocking maneuver reduces sample heating for heat sensitive materials. Beam alignment is assisted by fluorescence of the Ti specimen holder. Ion sources in the basic configuration of IV3 and IV4 are water-cooled TELETWIN ion guns operating at 2–10 keV with Ar+ ions. Optionally these ion sources can be replaced with one focused high-energy ion gun (2 to 10 keV) to achieve high (>350 µm/h) thinning rates or a low-energy hot-cathode focused ion gun (100 to 2000 eV), which guarantees clean specimen surfaces without amorphization. All combinations of ion sources are available for both IV3 and IV4.

Specimen exchange

IV4 is equipped with an air-lock sample exchange system, which guarantees a clean milling environment, minimizes sample contamination and supports high-throughput applications.

Large transparent regions

The exclusive design of IV3 and IV4 permits the preparation of extremely large (>100 µm2) TEM transparent areas.

Retarding field

The retarding field operation is now a standard feature of IV3 and IV4. This extension was developed to eliminate preferential sputtering and ion shadowing at low-angle bombardment. The incident ion beam is bent over the sample surface with a retarding field ranging from 0 to 2.5 keV. This method also eliminates preferential etching due to the grazing incidence.

Optional reactive ion milling, liquid nitrogen cooling and ion beam slope cutting

Several optional features are available for IV3 and IV4 in order to broaden the range of materials that could be prepared in our ion mills. Chemically assisted ion bombardment significantly reduces preferential sputtering. In compound semiconductors like GaAs the Ar+ milling also produces artifacts. IV3 and IV4 utilize iodine as chemically active ions for artifact-free preparation. Standard sample holders for IV3 and IV4 can be equipped with liquid nitrogen cooling. This feature reduces excessive sample heating during the low-angle ion bombardment. Thus, heat-sensitive materials can also be prepared without destabilization of internal structures. IV3 and IV4 can also be used for ion beam slope cutting for SEM applications with Hauffe sample holders. Samples thick as 5 mm can be cut in the ion mills.

Application

The system can be applied widely in the fields of Materials Research, Nanotechnology, Semiconductors and Optical Industry such as multilayer systems- wafers, semiconductors, high Tc superconductors, diamond, composite materials, metals, ceramics, glasses, Geology- rocks and minerals. The equipments are also suitable for the preparation of special sensitive materials.

• plan view and cross sectional specimens for TEM investigations
• slope cut specimens for SEM

Specifications

Ion source - Standard configuration:

• 2 water-cooled TELETWIN ion guns
• Variable, manually adjustable ion energy (2 to 10 keV)
• Variable, manually adjustable ion current
• Highest thinning rate (Si/30°): 200 µm/h

Focused high-energy ion gun (optional)

• Highest thinning rate (Si/30°): 350 µm/h

Focused low-energy ion gun (optional)

• Variable, continuously adjustable ion energy (100–2000 eV)
• Variable, continuously adjustable ion current (7–90 µA)
• Highest thinning rate (Si/30°): 28 µm/h

Specimen adjustment

Standard configuration, two sample holders supplied - one for single side, one for double side polishing:

• Cu sample holders (20 mm) with Ti cog-wheels
• Sample rotation speed: 3 to 5 rpm
• Sample oscillation angle: ± 0° to 90°
• Sample tilting: 0° to 90°
• Standard double-sided sample holder’s minimum angle of incidence: 3°
• Single-sided sample holder’s angle of incidence: 0° to 90°

Hauffe-sample holder (optional):

• Designed for ion beam slope cutting for SEM applications

Retarding field

• Retarding voltage: 0 to 2.5 kV
• Maximum current of the retarding source: 1 mA
• Gas supply: <1cm3/min (Ar gas)

Optical termination

• Minimum perforation diameter for thinning termination (nontransparent materials, metals): <40 nm
• Minimum sample thickness for thinning termination for Si without perforation: <100 nm

Vacuum system

• Pfeiffer vacuum system with oil-free membrane and turbomolecular vacuum pumps, equipped with compact full range gauge (operating with Pirani and Penning heads)
• Load-lock sample exchange system (for IV4)

Specimen observation

• NIKON SMZ 660 stereooptical microscope with transmitted and reflected illumination: continuously variable magnification with 8–50× zoom objective
• High-performance stereooptical microscope (optional)
• CCD camera based visual control system including a video lens, color CCD camera, camera support and 15” TFT monitor (optional)

Cooling stage (optional)

Liquid nitrogen cooled stage for heat-sensitive materials (available for all standard specimen holders)

Size / weight Vacuum chamber

• width: 190 mm, height: 225 mm
• weight: ca. 7 kg (15.6 lbs)

Power supply

• width: 450 mm, height: 267 mm, depth: 305 mm
• weight: 17 kg

Power requirements

• 100–120 V / 2.0 A / 60 Hz or 220–240 V / 1.0 A / 50 Hz
• single phase
• Cooling water supply: 0.5 l /min

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