Verfasst: 25.07.2016 11:04
Hello, this is my list of the today's questions of the exam "3D Integration" by Prof. Iuliana Panchenko.
- A figure was shown and you had to determine if it was 2.5D or 3D integration. Furthermore was asked to describe 2.5D and 3D integration.
- Via First: Which materials can be used as filling materials (name 3); which material would you use for filling if yuo have a via first process (and why)?
- DRIE: decribe BOSCH process (with sketches); which parameters have an impact on the etch rate? And a figure was shown in which you have to explain why larger TSV diameters cause deeper TSV lengths.
- WET and LASER: What is the first step of wet etching? Name 3 advantages and disadvantages of LASER drilling.
- Thin-film: sketch a CVD chamber. which materials are used for a barrier layer? Why is magnetron sputtering better than conventional sputtering?
- Via Filling: which materials can be used to fill a via? write down the chemical reactions at cathode and anode.
- Metallization: Sketch RDL Cu line process. Why is copper a very good material to use?
- Bonding/ Debonding: Describe chemical debonding and bonding techniques. Name the materials of carrier and adhesive. Why is a high TTV not good for further processing? Name Quality parameters.
- Grinding: Describe the DBG process. Name the aims of the stress relief and you want to etch 20um in 1 min - which stress relief technology do you use?
- Bonding: what is the difference between direct and indirect bonding? Name 2 examples each. Describe the SLID bonding. (figure was given and you had to name the different components).
- Which technological parameters have to be considered for fine-pitch bonding (6)-
- Cu TCB: Name 4 advantages of Cu TCB. How can you even improve this process?
- Metrology: 3 different cases were given and you should say which technology might be the best for analysis.
- Something to nanoporous connections (formation).