Top 4 Methods to Inspect Wafers
Due to the advancement in science, more and more gadgets and systems are being developed. As the number of tech tools increase, it becomes difficult to inspect them on a regular basis. The process of producing silicon wafers and chips is facing a similar fate.
Even with the best inspection tools and guidelines in place, detecting up to 30 nanometer defects in silicon wafers may still prove difficult.
However, chipmakers can rely on the following effective wafer inspection methods to identify common un-patterned defects.
1. Electron-Beam Inspection
Although electron-beam inspection is mainly used for engineering analysis, it is also the first line of defense against small defects. The method involves using a highly focused beam to look for the tiniest of all defects in a silicon wafer.
If used properly, the e-beam can trace defects of up to three nanometers. However, e-beams offer a very slow throughput. So if you want to speed up the wafer production and inspection process, using e-beams may not be a good idea.
2. Brightfield Inspection
Brightfield inspection uses 193 nanometer light sources, and it is one of the best ways to spot various defects in wafers. The technology works by collecting the light that reflects from a defect, and the defect then appears as a dark spot against a white background.
Brightfield inspection can easily trace defects of up to 30 nanometers. However, the method may not prove effective in detecting defects that range between 10 to 20 nanometers. Scientists are currently working on improving the brightfield method to identify the smallest possible defects.
3. Multi-Beam Inspection
The multi-beam inspection was introduced as a way to overcome the slow throughput of the e-beam detection method. However, multi-beam inspection will not entirely eliminate e-beam and optical wafer inspection methods.
One of the limitations of multi-beam inspection is that it uses various beams with different electrons. If these electrons collide with each other, it could impact the overall performance and efficiency of this inspection method.
4. Darkfield Inspection
Like the brightfield inspection method, darkfield is an optical technology. It simply measures the light reflected at a lower angle.
Whether you need help inspecting silicon wafers or a high-quality system that identifies detects at high throughputs, get in touch with a Lab Pro experts today!