Gate stack of nanocrystal memory and method for forming same

• Main Authors: SMITH, PHILIP O, LOJEK, BOHUMIL
• Format: Patent
• Language: Chinese; English
• Published: 16.01.2006
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A nanocrystal memory gate stack and a method for forming same includes first forming a first thermal oxide layer on a surface of a substrate followed by forming a control layer dielectric over the first thermal oxide layer. The control layer dielectric contains a plurality of nanocrystals. A polycrystalline gate is formed over the control layer dielectric and portions or the control layer dielectric that are not covered by the polycrystalline gate are etched until a plurality of nanocrystals not located under the polycrystalline gate is exposed. The exposed plurality of nanocrystals is consumed by employing a thermal oxidation process. A remaining plurality of nanocrystals located under the polycrystalline gate forms a floating gate and the thermal oxidation process produces a second thermal oxide. The second thermal oxide layer is anisotropically etched to form oxide spacers surrounding the polycrystalline gate.