| 摘要 |
<p>An IGBT is formed in a thin (less than 250 microns thick) float zone silicon wafer (20) using a hydrogen implant to form an N+ buffer layer (30) at the bottom of the wafer. A weak anode (21) is formed on the bottom of the wafer. A single hydrogen implant, or a plurality of hydrogen implants of progressively shallower depth and increasing dose can be used to form the implant in a diffused float zone wafer. The process may also be used to form an N+ contact region in silicon to permit a good ohmic contact to the silicon for any type device.</p> |
