A New Development to Eliminate Artifacts during TEM Sample Preparation in the FIB

Transcription

1 Inspire Innovation Through Collaboration High Technologies America, Inc. A New Development to Eliminate Artifacts during TEM Sample Preparation in the FIB

2 (Un)traditional FIB Preparation A Common Problem TEM preparation for lift-out has mostly become routine work on FIB-SEM systems recently, with standardized techniques that often are left to automation. Several papers addressing ion induced artifacts can be found when preparing lamellas at low kv relating to complex microstructures which often describe complex practices. Finalization of a lamella has mostly become: non-routine unreliable Driven by user experience level (varied results, not repeatable)

3 (Un)traditional FIB Preparation A Common Problem End Point Detection Signal & Scanning System Solution Several factors that typically are key to reduce/eliminate ion beam induced artifacts include: Scan conditions Ion species Sample orientation Ion beam incident angle Reproducibility?

4 End Point Detection Ion Milling Observation Signals BSE - Detector 2kV In-Lens SE Detector 2kV Simultaneous Observation Cut & See Observation Several users tend to view while thinning, more often than necessary. An SEM column with in-column filtering for the separation of signals such as SE and BSE are essential for identifying the target end point within a sample. Viewing the lamella while ion milling can be challenging due to high SE signal generation.

5 Ion Species A Common Problem Damage Ion Species Solution The ion beam can be approximated as a continuous heat source. At shorter times, there are large temporal variations in heating, and at times of less than s, the atoms barely have time to interact with each other, and the temperature of the solid is not well defined. SEM Ref: MRS BULLETIN VOLUME 32 MAY 2007 www/mrs.org/bulletin Ar- Beam

6 Ion Species Ion Induced Damage Effects Damage Gallium Ion Gate Poly Si Gate Oxide Si sub 65nm NAND Flash 30kV Final Polishing

7 Ion Species Ion Induced Damage Effects Damage Gallium Ion Gate Poly Si Gate Oxide 5nm Si sub 5kV Ga Final Polishing 65nm NAND Flash

8 Ion Species Real Time Fabrication with Low kv ArB Ion column Localized thermal/stress effects during Ga ion milling can induce bending, which increases the likeliness of losing your lamella FIB Ar beam is broad and gentle. Ar

9 Ion Species Real Time Fabrication with Low kv ArB Ion column Low energy Ar broad ion milling is less destructive and removes amorphous material left behind by Ga milling FIB Ar beam is broad and gentle. Ar

10 Sample Orientation A Common Problem Curtain Effect Sample Orientation Solution Sample orientation with respect to ion incidence angle can influence the planarity of the cross-section face.?

11 Anti-Curtaining Function Ion Milling Result for 7-Axis Stage SIM image of TEM lamella processed by S-axis±15. DRAM from Game Machine TEM image (Acc.: 200kV)

12 Anti-Curtaining Function Ion Milling Result for 7-Axis Stage SIM image of TEM lamella processed by S-axis±15. DRAM from Game Machine TEM image (Acc.: 200kV)

13 Enhancing Reproducibility A Common Problem Throughput Software + Hardware Productivity, throughput and repeatability are comprised by synergy between: User Application Hardware* Ref:

14 Summary ACE Technology Solution A host of functions and components to reduce FIB related artifacts, called ACE [Anti Curtaining Effect] Technology have been developed that employ Ar/Xe ion beam milling and automated sample orientation control. The 7-axis stage, automated sample orientation control and combined triple beam FIB-SEM configuration, all of which essentially make up the ACE Technology suite. The processing of cutting edge devices in a FIB-SEM often requires specialized techniques and specific functions for producing ultra-thin lamella. The latest FIB-SEM platform offers these innovations for reliability, repeatability and high quality lamella preparation for Cs Corrected (S)TEMs.

15 END Thank You! Jamil J. Clarke High Technologies