Unusual informations of PN-diode

Question

There are several variables like: concentration of electron deficiencies/holes or electrons (n,p) in p/n-type of semiconductor, concentration of donor or acceptor atoms (Nd,Na) in doped semiconductors, length of pn-juction of diode, electron or hole mobility constant (Dn,Dp), etc.

But all of these variables are unreachable for me. At the beginning I thought at least datasheets should include such data but they don't. Just the ones used practically.

Where/How can I access this kind of information?

• BTW: All these variables matter for calculating electron/hole average speed (v), current flux(Φ), density of current (J), which are more theoretical calculations. There are also more practical ones like junction capacitance (matters when reverse-biased) and diffusion capacitance (matters when forward-biased).

Answer 1

Manufacturers of semiconductor devices are very unlikely to give out these values. There are a number of reasons for this.

You don't need it to design circuits

In fact, it isn't even useful for designing circuits. The datasheet will give you the information you need. There is no reason to calculate an I-V curve when you can just grab it from the datasheet.

Their devices are more complicated than the basic models you learned about.

The manufacturer would have to disclose many more details about their process in order for things like dopant concentrations to be useful. This includes low level device structure, and possibly process details.

They consider it proprietary

Manufacturers are going to be reluctant to tell you anything more than you need to know. This is probably less true for very basic devices, like a diode. But without good reason, I can't envision a manufacturer of anything giving out more information about their process than is necessary.

You don't need it to design circuits (still)

All the theoretical calculations in the world are only so good as they model real life devices. If you test the device, you know how it behaves. Information from these tests is included in the datasheets.

Also, consider that there is unavoidable process variation. Your theoretical calculations can't account for this (at least not without much more insight into the manufacturing process than any manufacturer would freely give out). The datasheets, based on actual electrical measurements, can tell you everything you need about the variability.