Technology sharing: description of IC failure analysis steps

Date：2021-09-09 15:36:36 Views：1885

Integrated circuit failure analysis plays a vital role in improving the reliability of integrated circuits. Failure analysis of integrated circuits can promote enterprises to correct the problems in the process of design, experiment and production, implement control and improvement measures, prevent and reduce the recurrence of the same failure mode and failure mechanism, and prevent the recurrence of similar failure phenomena. This paper mainly describes the technology and steps of IC failure analysis.

IC failure analysis steps:

1. Inspection before opening, appearance inspection, X-ray inspection and scanning acoustic microscope inspection.

2. Open the seal for microscopic examination.

3. Electrical performance analysis, defect location technology, circuit analysis and microprobe analysis.

4. Physical analysis, delamination, focused ion beam (FIB), scanning electron microscope (SEM), transmission electron microscope (SEM), VC positioning technology.

1、 Nondestructive failure analysis technology

1. Appearance inspection mainly relies on visual inspection to check whether there are obvious defects, such as whether the plastic grease package is cracked and whether the chip pins are in good contact. X-ray inspection is to irradiate the tested sample with X-ray perspective performance. The defective part of the sample will absorb X-ray, resulting in abnormal X-ray irradiation imaging. X-ray is mainly used to check whether the IC lead is damaged. Select the appropriate wavelength according to the size and structure of electronic components, so as to obtain the appropriate resolution.

2. Scanning acoustic microscope uses ultrasonic to detect the internal defects of the sample and find out the location of the internal defects of the sample according to the reflection of ultrasonic. This method mainly uses the damage of moisture or high temperature to the device during plastic packaging of the main integrated circuit, which is often crack or delamination.

2、 Lossy failure analysis technology

1. There are generally three methods to open the package. Full stripping method, the integrated circuit is completely damaged, leaving only the complete internal circuit of the chip. The defect is that the internal circuit and leads are all damaged, so the electromotive state analysis can no longer be carried out. Methods two Bureau total division method, three grinder grinds the resin on the surface of integrated circuit until the chip. The utility model has the advantages that the unsealed seeds do not damage the internal circuit and leads, and the electromotive state analysis can be carried out after unsealing. The third method is to use sulfuric acid injection to achieve the effect of local removal.

2. Defect location, locating specific failure location is an important and difficult item in integrated circuit failure analysis. Failure mechanism and defect characteristics can be found only after defect location.

a. Emission microscope technology has the characteristics of non-destructive, fast and accurate. It uses optoelectronic detectors to detect areas where optoelectronic effects occur. Due to the defects in the silicon wafer, the increasing electron hole recombination usually occurs, resulting in strong photon radiation.

b. OBIRCH technology is a measurement technology that uses laser beam to induce the change of material resistivity. By scanning different materials with laser beam, the resistivity changes of different materials can be obtained. This method can test the reliability hidden dangers in metal wiring.

C. Liquid crystal hot spot detection is generally composed of polarizing microscope, sample table with adjustable temperature and control circuit. When changing from crystal anisotropy to crystal isotropy, the critical temperature energy required is very small, so as to improve the sensitivity. At the same time, the phase transition temperature should be controlled at 30-90 degrees, and the polarization microscope should be used in orthogonally polarized light, which can improve the sensitivity of liquid crystal phase transition reaction.

3. Electrical performance analysis (probe table)

According to the layout and schematic diagram of the decorative circuit, combined with the chip failure phenomenon, gradually reduce the circuit range of the defective part, and finally use the microprobe microscopy technology to locate the defective device. Microprobe detection technology. The function of microprobe is to measure the electrical parameters on internal devices, such as working point voltage, current and volt ampere characteristic curve. Microprobe technology is generally used together with circuit analysis, which can quickly search for failed devices.

3、 Physical analysis

1. Focused ion beam (FIB) is composed of ion source, ion beam focusing and sample stage. An electron microscope was used to focus the ions into a microwave sized cutter. The fine and accurate cutting of focused ion beam, combined with the high-resolution imaging of scanning electron microscope, can well solve the profile problem, and the positioning accuracy can reach less than 0.1um. At the same time, the stress in the profile process is very small, and the integrated circuit can be preserved completely.

2. Scanning electron microscope (SEM) uses focused ion beam to bombard the surface of the device to generate many electronic signals. These electronic signals are amplified as modulation signals and connected to the display to obtain the device surface image.

Transmission electron microscope (TEM), with a resolution of 0.1nm, can clearly analyze device defects and better meet the analytical requirements of integrated electrical failure analysis for detection tools.

3. VC positioning technology scans the sample surface based on the primary electron beam or ion beam of SEM or fib. There are different potentials at the missing parts of the silicon wafer surface, showing different bright contrast. Find out the points that are normally bright, so as to locate the failure point.

In conclusion, I believe that by reading the above integrated circuit failure analysis technologies and steps, we have a preliminary understanding of failure analysis, a deeper understanding of the application of various technologies, and we also need to accumulate experience in the actual analysis work. At the same time, I hope you can make a summary in the learning process, so as to continuously improve your professional level.