Issued Date: 2017/5/23
Issued By: iST
Communication chips failed and the bug indicator tells there is a hot spot in existence.
Where is it and how to identify causes to this failure?
Communication chips differ from most other silicon ones in their simpler package and fewer layers. It’s better not delayering the sample gradually for hot spot identification as the defect may get removed at the same time.
In addition, communication chips are most likely made of InP and GaAs which are prone to corrosion by acid solutions. This mandates specific acid solutions for sample decapsulation. As a matter of fact, communication chips made by different process may necessitate solutions of specific formula.
After a sample is ready the next step is to employ series of failure analysis tools to pinpoint its bugs. How? Let us present two typical cases by iST to learn about its dealing with communication IC failure by identifying hot spot in no time.
Case 1: Hot spot detection of leaking fiber optic communication component failed from P-electrode. It's not the case after switched to the N-electrode.
The hot spot of leaking fiber optic communication component was shielded off by the thicker metallic layer at the P-electrode as shown in Figure 1-1. The special sample preparation method employed by iST enables it to identify hot spot in no time after changing to detect a leak at N-electrode (Figure 1-2).
Once the source of leak was found in a larger scope structure of microscopic slices out of it, it tells us that there are defects existing in the joint between metal and substrate layers (Figure 1-3), i.e. they are deteriorating the communication component and leading to a leak.
Figure 1-1: Leak not found in P-electrode
Figure 1-2: Leak is found in N-electrode
Figure 1-3: Slice analysis tells that there are defects existing at the joints
Case 2: Acid solution plays a key role in sample preparation. iST identified defects in microwave communication components in two simple steps
When preparing a decapsulation of microwave communication component, the sample is likely to suffer acid corrosion. iST exclusive acid solution formula along with precision failure analysis tools enable it to:
(1) Identify hot spot in larger scope with OBIRCH (Figure 2-1)
(2) Dual beam FIB slicing (Figure 2-2) unveils defect in the dielectric oxide layer immediately! The burnt out insulation layer leads to a leak at top and bottom electrode metals.
We are more than glad to share our test experiences with you. In case of any needs about IC failure analysis, please call Mr. Fang at +886-3-579-9909 Ext. 6773 or send him an email at email@example.com.