DECOUPLED VIA FILL

• Main Authors: BRAIN, RUTH A, INDUKURI, TEJASWI K, GRIGGIO, FLAVIO, SHUSTERMAN, YURIY V
• Format: Patent
• Language: Chinese; English
• Published: 01.10.2020
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Techniques are disclosed for providing a decoupled via fill. Given a via trench, a first barrier layer is conformally deposited onto the bottom and sidewalls of the trench. A first metal fill is blanket deposited into the trench. The non-selective deposition is subsequently recessed so that only a portion of the trench is filled with the first metal. The previously deposited first barrier layer is removed along with the first metal, thereby re-exposing the upper sidewalls of the trench. A second barrier layer is conformally deposited onto the top of the first metal and the now re-exposed trench sidewalls. A second metal fill is blanket deposited into the remaining trench. Planarization and/or etching can be carried out as needed for subsequent processing. Thus, a methodology for filling high aspect ratio vias using a dual metal process is provided. Note, however, the first and second fill metals may be the same.