OM: Optical microscope (abbreviated as OM) is an optical instrument that uses optical principles to magnify and image small objects that cannot be distinguished by the naked eye, allowing people to extract microstructure information. It can observe the crystal structure and surface defects of materials.

 

surface

 

 section

 

SEM: Scanning electron microscope (SEM) is a large-scale precision instrument used for high-resolution micro area morphology analysis. It has the characteristics of large depth of field, high resolution, intuitive imaging, strong stereo sense, wide magnification range, and the ability to rotate and tilt the tested sample in three-dimensional space. In addition, it has the advantages of rich types of measurable samples, almost no damage or pollution to the original sample, and the ability to simultaneously obtain morphology, structure, composition, and crystallographic information. At present, scanning electron microscopy has been widely used in micro research in fields such as life sciences, physics, chemistry, justice, earth sciences, materials science, and industrial production. In the field of earth sciences alone, it includes crystallography, mineralogy, mineral deposits, sedimentology, geochemistry, gemology, micropaleontology, astronomical geology, oil and gas geology, engineering geology, and structural geology.

As for the application of scanning electron microscopy in the integrated circuit manufacturing industry, it can be mainly divided into five categories:

1. Morphological observation

2. Measurement reference;

3. Cross section observation;

4. Surface observation;

5. EDX analysis (rapid elemental microanalysis, pre scanning, surface scanning)

Semiconductor chip samples

 

       1.FIB: Focused Ion Beam (FIB) is a micro cutting instrument that uses an electric lens to focus ion beams into very small sizes. FIB is the process of accelerating ion beams generated by ion sources (most FIBs use Ga, and some devices have He and Ne ion sources) through an ion gun, focusing them, and then acting on the surface of the sample.

       The basic functions of a focused ion beam microscope can be roughly divided into four types:

       1. Fixed point cutting - using the physical collision of ions to achieve the purpose of cutting. Widely used in Cross Section processing and analysis of integrated circuits (ICs) and LCDs.

       2. Selective material evaporation plating - decomposing organic metal vapor or gas-phase insulation materials with the energy of ion beams, depositing conductors or non-conductors in local areas, providing metal and TEOS deposition. Common metal deposition methods include platinum (Pt) and tungsten (Tungsten, W)

       3. Enhanced etching or selective etching - supplemented by corrosive gases to accelerate cutting efficiency or perform selective material removal  。

       4. Etching endpoint detection - detects the signal of secondary ions to understand the progress of cutting or etching

       Our company uses a dual beam model (ion beam+electron beam). When cutting with an ion beam, we use an electron beam to observe the image, in addition to avoiding the continuation of the ion beam; Destruction site" In addition, it can effectively improve image resolution, and can also be equipped with an X-ray spectrometer or secondary ion mass spectrometer for elemental analysis. The diverse analysis functions greatly improve the convenience and usage rate of focused ion beam microscopy. Our FIB is equipped with a STEM probe, which can achieve transmission imaging of TEM samples at 30Kv. The electronic imaging boundary is clear but difficult to identify, STEM transmission, and the internal morphology is unobstructed.

       As for the application of ion beam microscopy in the integrated circuit manufacturing industry, it can be mainly divided into five categories

       1. Line repair and layout verification;

       2. Component fault analysis;

       3. Analysis of abnormal production line processes;

       4. IC process monitoring - such as photoresist cutting;

       5. Preparation of transmission electron microscope specimens.

 

(a) On the figure, the failure analysis of FIB/SEM revealed that the metal layer was broken, and the low energy EDX analysis revealed that the nitride layer was in the defect area< Br/> (b) Below the figure: Using voltage comparison (VC), the failure location can be determined. Using FIB's cross-sectional processing, SEM can observe the disconnection of the metal layer connection, resulting in a bright and dark VC.

 

The image shows the preparation of TEM samples using FIB. The left image shows the cut scanning electron microscope image, while the right image shows the sample holder with nanoneedle extraction attached to TEM before proceeding to transmission electron microscopy work