3D NAND TEM Specimen Preparation by FIB-SEM

Introduction

FIB-SEM is a system integrating fine processing by using a Ga ion beam and observation & analysis function by SEM. This feature enables precise preparation of TEM specimens while checking cross-sectional images during processing. In particular, in the field of semiconductors where miniaturization continues, it is widely used for a TEM specimen preparation from the desired location. 3D NAND is a NAND type flash memory and is widely adopted in the storage device of a smartphone and PC. It consists of regularly stacked fine structures ranging from tens to hundreds of nanometers (Figure 1). TEM analysis is generally performed for quality testing. Therefore, the FIB-SEM is indispensable for high-precision specimen preparation prior to TEM observation.
In this application note, we used the FIB-SEM system "JIB-PS500i" (Figure 2), which incorporates a high-resolution SEM and supports a streamlined STEM workflow, to obtain SEM images and prepare TEM specimens from three directions of the 3D NAND structure. The TEM observation results obtained are presented.

Steps of TEM specimen preparation by FIB

In TEM specimen preparation using the FIB for 3D NAND, the conventional method involves cutting a block from the substrate material, mounting it onto the FIB grid, and then thinning the block. With JIB-PS500i, since the stage can be tilted by more than 90 °, confirmation of TEM specimens using STEM is possible without removing them from the system (Figure 3). This function allows for preparing a high-quality TEM specimen targeting a specific location.

Figure. 3 Flow of TEM specimen preparation by using JIB-PS500i

Results

SEM images and SEM-STEM images (taken by JIB-PS500i), and TEM-STEM images (taken by JEM-ARM200F) from three directions (Figure 4 to 6)  are shown below.

Figure. 4 SEM image, STEM image (JIB-PS500i) and TEM image (JEM-ARM200F) taken from YZ direction

Figure. 5 SEM image, STEM image (JIB-PS500i) and TEM image (JEM-ARM200F) from XZ direction

Figure. 6 SEM image, STEM image (JIB-PS500i) and TEM image (JEM-ARM200F) from XY direction

Conclusion

• Using the JIB-PS500i, SEM observation and TEM specimen preparation for 3D NAND were performed from three directions.

• High-quality TEM specimens can be prepared even for fine semiconductor structures such as 3D NAND, due to the high-resolution SEM image and easy STEM observation.

Solutions by field

Semiconductor

Electrical / Electronic Component

Related products

JIB-PS500i FIB-SEM system

JEM-ARM200F NEOARM Atomic Resolution Analytical Electron Microscope