Method for forming a semiconductor device with a tailored well profile

• Main Authors: SULTAN AKIF, HAUSE FREDERICK N
• Format: Patent
• Language: English
• Published: 12.02.2002
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A method for forming a semiconductor device is provided. A base layer is provided. A first epitaxial layer having a first dopant at a first concentration is formed above the base layer. A second epitaxial layer having a second dopant at a second concentration is formed above the first epitaxial layer. The second concentration is greater than the first concentration. A third epitaxial layer having a third dopant at a third concentration is formed above the second epitaxial layer. The third concentration is less than the second concentration. Ions are implanted in the third epitaxial layer to form an implant region. The implant region is in contact with the second epitaxial layer. A semiconductor device comprises a base layer, first, second, and third epitaxial layers, and an implant region. The first epitaxial layer has a first dopant at a first concentration disposed above the base layer. The second epitaxial layer has a second dopant at a second concentration disposed above the first epitaxial layer. The second concentration is greater than the first concentration. The third epitaxial layer has a third dopant at a third concentration disposed above the second epitaxial layer. The third concentration is less than the second concentration. The implant region is defined in the third epitaxial layer and is in contact with the second epitaxial layer.