Summary: detailed steps of semiconductor failure analysis and test

Date：2021-04-26 16:29:00Views：2218

Failure analysis sample preparation: failure analysis is an important part of chip testing. Whether for mass production samples, design links or customer returned products, failure analysis can help reduce costs and shorten the cycle.

Common failure analysis methods include decap, X-ray, IV, Emmi, FIB, SEM, EDX, probe, OM, RIE, etc. because failure analysis equipment is expensive, most demand units can not match or complete the required equipment. Therefore, it is also a good choice to use external forces and open resources to complete their own analysis. What information do we need to prepare when we choose to test outside? Let's sort it out for you:

IOpen the coverdecap: write down the sample size, quantity, packaging form, material and unsealing requirements (if it is on the PCB board, it is best to remove it in advance, and the PCB board has large protrusions, which will affect the protection of the chip) and subsequent tests.

1. IC unsealing (front / back) QFP, QFN, sot, to, dip, BGA, cob, etc

2. Sample thinning (except ceramics and metals)

3. Laser marking

4. Chip unsealing (front / back)

5. IC etching and plastic package removal

IIX-RAY: write down the sample size, quantity, material (high density can be seen, low density can be directly penetrated), key observation area and accuracy.

1. Observe electronic components such as semiconductors, resistors, capacitors and small PCB printed circuit boards with different packages such as dip, SOP, QFP, QFN, BGA and flipchip

2. Observe the chip size, quantity, stacking die and wire binding inside the device

3. Observe chip crack, uneven dispensing, broken wire, grounding, internal bubbles and other packages

Defects, as well as solder ball cold welding, false welding and other welding defects

IIIIV: write the number of pigging pins, packaging form, power on mode, voltage and current limit range. The laboratory personnel need to confirm in advance to build a suitable analysis environment. If the sample is not suitable, there is no need to go in vain.

1.Open/Short Test

2.I/V Curve Analysis

3.Idd Measuring

4. Powered leakage test

IVEMMI: write down the power on mode, voltage and current of the sample, whether it is a bare die, whether it has been opened, special requirements, etc. Emmi is a power on test. You can connect various source meters to confirm the power on requirements. If the laboratory does not have a suitable source meter, you can bring it yourself to avoid useless work.

1. P-n interface leakage; P-n interface collapse

2. Hot electron of saturation region transistor

3. Photon excitation generated by oxide leakage current

4.Latch up、Gate Oxide Defect、Junction Leakage、

Hot carriers effect, ESD and other problems

VFIB: write down whether the sample size, material and conductivity are good. If the size is large, it needs to be cut in advance. Generally, the sample table is about 1-3cm, too large samples can not be put in, and image positioning is also required. The samples with good conductivity can be analyzed quickly, and the samples with poor conductivity need auxiliary measures for better analysis. For tangent point observation, the requirements for tangent point shall be clearly marked. Write out the tangent connection scheme and send the positioning file.

1. Chip circuit modification and layout verification

2. Cross section analysis

3.Probing Pad

4. Fixed point cutting

ViSEM: write down whether the sample size, material and conductivity are good. If the size is large, it needs to be cut in advance. Generally, the sample table is about 1-3cm, too large samples can not be put in, and image positioning is also required. The samples with good conductivity can be analyzed quickly, and the samples with poor conductivity need auxiliary measures for better analysis.

1. Material surface morphology analysis and micro area morphology observation

2. Analysis of material shape, size, surface, section and particle size distribution

3. Surface morphology observation, film roughness and film thickness analysis of film samples

4. Nano size measurement and marking

VIIEDX: write down the sample size and material. EDX is a qualitative analysis, which can see the material and approximate proportion of the sample, which is suitable for metal element analysis.

1. Qualitative analysis of micro component

VIIIProbe: write down the requirements of sample test environment, what source table to match and what probe to use. Generally, there are hard needle and soft needle. The soft needle is thin, which is not easy to cause secondary damage to the sample.

1. Small connection point signal leading out

2. Failure analysis and failure confirmation

3. Confirmation of electrical characteristics after modification of FIB circuit

4. Wafer reliability verification

IXOM: write down the sample and the requirements for magnification. Om belongs to surface observation and cannot see the internal situation.

1. Sample appearance and morphology inspection

2. Metallographic and microscopic analysis of prepared samples

3. Search for various defects

4. Transistor spot welding and inspection

XRIE: write down the sample material and the area to be seen.

1. For isotropic and anisotropic etching of materials using fluorine based chemistry, including carbon, epoxy resin, graphite, indium, molybdenum, nitrogen oxide, photoresist, polyimide, quartz, silicon, oxide, nitride, tantalum, tantalum nitride, titanium nitride, tungsten titanium and tungsten

2. Etching of device surface pattern.