Semiconductors industries

Thread Starter

nok

Joined Jul 28, 2010
33
Before approximate 8 months I read that some big companies begin to invest a lot of money in change the wafer size from 300 millimeters diameter to 450 millimeters diameter, in these days one friend tell me that he hear that all the industries in semiconductors stop all these processes and all the semiconductors industries will stay with wafers that have 300 millimeters diameters, because I am not sure that it is true and I don't understand what happen so I try to find in google some articles that will confirm it or disprove and will give information and details for these two options (confirmation or disprove) like:
1. If it was stop so why the semiconductors industries stop to the research and development to move from 300 millimeters diameter wafers to 450 millimeters diameter wafers?
2. If it was not stop so what are the advantage and disadvantages from moving from 300 millimeters diameter wafers to 450 millimeters diameter wafers?
 

wayneh

Joined Sep 9, 2010
17,153
Imagine making pizza. It's almost as much work to make a small one as a large one. More chips per wafer increases efficiency.

I don't follow the industry but if everyone bailed out of the larger wafers, they must have all encountered a hurdle that must wait for improved technology.
 

Papabravo

Joined Feb 24, 2006
17,041
I guess it must be the cost. Growing and processing wafers of silicon is not a process that scales linearly. As the feature size declines, the yield on a wafer with 50% more area might also decline as well. A well refined process requires a yield on the order of 98% or better.
 

crutschow

Joined Mar 14, 2008
27,967
450mm is an enormous wafer and boule size.. I would think it be quite difficult to cut those thin wafers from such a large boule and still keep them flat and of uniform thickness. Perhaps it was these mechanical issues that slowed their development.
 

wayneh

Joined Sep 9, 2010
17,153
The industry situation reminds me of the classic game theory situation, the prisoner's dilemma (Google it). No one is going to embrace the technology first, because of the risks and costs. Those fears go out the window if the other guy makes the move. Then, the risk comes from not doing it.
 

nsaspook

Joined Aug 27, 2009
8,796
We have learned how to do 3D fabrication on the cheap with existing tools. This has reduced the need for larger wafer sizes but has greatly increased the complexity and sensitivity of the process controls needed to maintain quality. IMO most of the 450mm guys are refining the process at 300mm to the point that 450mm is just not worth the 3x cost for 2x the product in the current market.
 

ian field

Joined Oct 27, 2012
6,539
Imagine making pizza. It's almost as much work to make a small one as a large one. More chips per wafer increases efficiency.

.
Not really - they have to grow the larger ingot from a seed crystal, that involves touching a seed crystal down to the silicon melt pool, then drawing it up *VEEEEEERY* slowly. Its not an easy thing to do and they're doing it as big as they've figured out how to so far.

The increased difficulty doesn't end there, they have to slice the bigger ingot into very thin wafers - not easy to avoid fractures.

Some defects can scrap a whole wafer - some ingot defects can scrap a whole sequence of wafers.
 
Top