Method for making a charge balanced multi-nano shell drift region for superjunction semiconductor device
US7892924B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2009 |
| Grant date | Feb 22, 2011 |
| Priority date | — |
| Expiry date | Dec 2, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/111
Abstract
A method is disclosed for making a substantially charge balanced multi-nano shell drift region (MNSDR) for superjunction semiconductor devices atop a base substrate. The MNSDR has numerous concentric nano shell members NSM1, NSM2, . . . , NSMM (M>1) of alternating, substantially charge balanced first conductivity type and second conductivity type and with height NSHT. First, a bulk drift layer (BDL) is formed atop the base substrate. A substantially vertical cavity of pre-determined shape and size and with depth NSHT is then created into the top surface of BDL. The shell members NSM1, NSM2, . . . , NSMM are successively formed inside the vertical cavity, initially upon its vertical walls then moving toward its center, so as to successively fill the vertical cavity till a residual space remains therein. A semi-insulating or insulating fill-up nano plate is then formed inside the residual space to fill it up.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.