Process for Making Self-Aligned Doped Regions for Storage Structures
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
The process described below makes it possible to fabricate shallow doped regions which are self-aligned to the electrode of a storage structure. The following process steps are described in conjunction with Figs. 1 and 2. 1. Form a dielectric layer 14 on a substrate 10. 2. Use low-energy ion implantation to form a shallow doped region 12 on a surface layer of the substrate 10. 3. Form an electrode structure 16 on the dielectric layer 14. 4. Use a low-temperature plasma oxidation step to consume (convert into oxide) a surface layer of he substrate which is not protected by the electrode structure, and form an oxide layer 18. Depending on the choice of electrode material, the thickness of this oxide layer over the electrode may differ from its thickness over the substrate.