Any good books on the physics of semiconductor devices? I know there are many books on semiconductor devices. But, it seems that many of them are catering to the engineers, not physicists. Namely, the books lack the theoretical depth. 
So, is there any good one explaining the physics to a decent level? 
 A: The question is always what is a 'decent' level...
There are many books that appear to deal with semiconductor device physics, but generally deal more with semiconductor technology. I have a number of those gathering dust on my shelf. The one that has stood the test of time since my graduate device physics course is S.M. Sze's Physics of Semiconductor Devices. When a device physics question comes up (my group does radiation effects on devices, so they come up often), I reach for Sze first. The one I used, and still have, is the second edition from 1981. I have no experience with the 2007 third edition, but a look at the table of contents looks like they have merely added material (primarily on optical devices). 
So, why Sze? By and large, he covers the full gory details of the physics of each device, and makes sure that you know where the more common approximations come from. There is an intro chapter on basics of semiconductors (structure, energy bands, carriers, phonons...). Then bipoplr devices (diodes, bipolars, thyristors) are covered. Part III has the unipolar devices (FETs, MOSFETS, CCDs). Part IV is microwave devices. Part V  is photonics  (LEDs, lasers, solar). Again, this is the second edition. It appears that the third adds more to the last section to take in to account the last 30 years of development there. 
If the detail in the text is not good enough, the references will have even more detail. However, I think you would need to get really really deep in before needing to go look up the original journal articles.
Finally, it looks like both editions are still generally available.
A: Semiconductor physics and devices by Donald A. Neamen is a pretty good book. I am using it. Everything is covered in a great detail there are 3 units for introduction, it really helps to build a strong base and always do the exercises completely it really helps to strengthen the core of the topic. 
