Reflection – Visualization for challenge on semiconductor process

Challenge & Selection

I am an engineer developing semiconductor manufacturing process. My challenge is to solve technical  problems such as a defect problem during semiconductor manufacturing process. We can improve yield  of memory device by solving defect problem. Defect problem happened during pilot production of high- end memory device. My favorite tool for finding solution is the visualization. After visualization of  process parameter and schematic of the process equipment, it is easy to engage with every stakeholders  and root-cause of problem can be captured by much higher possibility. Impact of visualization is  amazing. Semiconductor process is controlled by the recipe which is kind of table format of series of  numbers. It is not easy to capture the problem from the series of numbers but much easier to capture  the problem once after visualization of the parameter. Also, we have detailed drawings of each  hardware, but simple schematic drawing is more powerful than detailed drawings of individual  hardware.

Application

Recently, during pilot production of high-end memory device, we encountered a defect problem which  is critical to the manufacturing yield. A meeting was called after defining problem statement and success  criteria. We focused on visualizing each of the process parameters of the process. Series of control  parameter doesn’t show the problem well. However, after visualization of each process parameter, one  of the process parameter shows one outstanding pulse signal which captures attention from every  stakeholder. Discussion becomes enriched after this finding. Visualization of this parameter reveals that  there is un-necessary high flow on one step of the process. Also, it visualized that plasma is turned on  before having enough time to pump out this gas. One stakeholder who is an expert on plasma added a  comment that it is a disaster to turn on the plasma before fully removing this gas. One stakeholder who  is an experienced similar problem comment that this high flow will disturb all particles to the wafer.  Once after capturing the potential risk, next focus is the visualization of problem with schematic  drawing. Each stakeholder can be aligned on the same page and mechanism was built with high  confidence level. After having strong model of the root-cause and solution, it is not hard to pull out  additional resources to find a solution of this problem. Experimental plan was made based on this root- cause and solution model and the hypothesis was justified by the experiment. Eventually, we could  achieve dramatic improvement of defectivity by this approach.

Insight & approach

By conducting visualization tool application on my work, I could learn that how much visualization is  effective to (1) find potential risk & root-cause, (2) engage with stakeholders, (3) make consensus, (4)  mechanism model, (5) design experiment for solving problem. Since I experienced that visualization tool  is so effective for addressing a problem, I might also try series of other approach on this lesson for the  future.

