Abstract: A new method of forming a dual damascene structure involves forming a via-level precursor structure on a substrate and spin coating an oxide protective layer over the bottom anti-reflective coating, which is the last layer of the via-level precursor structure. A trench-level photoresist layer is deposited over the oxide protective layer to form a trench pattern etch mask. The oxide protective layer protects the BARC layer and the via plugs from photoresist removing process. When and if the trench-level photoresist layer is to be reworked, the trench-level photoresist layer is simply removed without removing the BARC layer and the via plugs under the oxide protective layer.

Abstract: A method for forming a dual damascene opening to protect a low-K dielectric insulating layer including providing a semiconductor process wafer comprising a via opening extending though a thickness portion of at least one dielectric insulating layer; depositing a first dielectric layer stack layer comprising at least one dielectric insulating layer over the at least one dielectric insulating to seal the via opening; blanket depositing a second dielectric layer stack comprising at least one dielectric layer to form a hardmask over and contacting the first dielectric layer stack; photolithographically patterning and etching through a thickness of the hardmask and the first dielectric layer stack to form a trench opening etching pattern overlying and encompassing the via opening while leaving the via opening sealed; and, etching through a thickness portion of the at least one dielectric insulating layer to form a dual damascene opening.

Abstract: A method for post-etch copper cleaning uses a hydrogen plasma with a trace gas additive constituting about 3-10 percent of the plasma by volume to clean a copper surface exposed by etching. The trace gas may be atomic nitrogen or other species having an atomic mass of 15 or greater. The trace gas adds a sputtering aspect to the plasma cleaning and removes polymeric etch by-products and polymeric and other residuals formed during the deposition of dielectric materials or etch stop layers over the copper surface. An anti-corrosion solvent may be used to passivate the copper surface prior to formation of the dielectric materials or etch stop layers.

Abstract: A plasma containing 5–10% oxygen and 90–95% of an inert gas strips photoresist from over a low-k dielectric material formed on or in a semiconductor device. The inert gas may be nitrogen, hydrogen, or a combination thereof, or it may include at least one of nitrogen, hydrogen, NH3, Ar, He, and CF4. The operating pressure of the plasma may range from 1 millitorr to 150 millitor. The plasma removes photoresist, the hard skin formed on photoresist during aggressive etch processes, and polymeric depositions formed during etch processes. The plasma strips photoresist at a rate sufficiently high for production use and does not appreciably attack carbon-containing low-k dielectric materials. An apparatus including a plasma tool containing a semiconductor substrate and the low oxygen-content plasma, is also provided.

Abstract: A plasma containing 5-10% oxygen and 90-95% of an inert gas strips photoresist from over a low-k dielectric material formed on or in a semiconductor device. The inert gas may be nitrogen, hydrogen, or a combination thereof, or it may include at least one of nitrogen, hydrogen, NH3, Ar, He, and CF4. The operating pressure of the plasma may range from 1 millitorr to 150 millitor. The plasma removes photoresist, the hard skin formed on photoresist during aggressive etch processes, and polymeric depositions formed during etch processes. The plasma strips photoresist at a rate sufficiently high for production use and does not appreciably attack carbon-containing low-k dielectric materials. An apparatus including a plasma tool containing a semiconductor substrate and the low oxygen-content plasma, is also provided.

Abstract: A method for forming a dual damascene including providing a first dielectric insulating layer including a via opening; forming an organic dielectric layer over the first IMD layer to include filling the via opening; forming a hardmask layer over the organic dielectric layer; photolithographically patterning and dry etching the hardmask layer and organic dielectric layer to leave a dummy portion overlying the via opening; forming an oxide liner over the dummy portion; forming a second dielectric insulating layer over the oxide liner to surround the dummy portion; planarizing the second dielectric insulating layer to expose the upper portion of the dummy portion; and, removing the organic dielectric layer to form a dual damascene opening including the oxide liner lining trench line portion sidewalls.

Abstract: A method of forming a dual damascene opening comprising the following steps. A structure having an overlying exposed conductive layer formed thereover is provided. A dielectric layer is formed over the exposed conductive layer. An anti-reflective coating layer is formed over the dielectric layer. The anti-reflective layer and the dielectric layer are etched using a via opening process to form an initial via exposing a portion of the conductive layer. A protective film portion is formed over at least the exposed portion of the conductive layer. The anti-reflective coating layer and the dielectric layer are patterned to reduce the initial via to a reduced via and to form a trench opening substantially centered over the reduced via. The trench opening and the reduced via comprising the dual damascene opening.

Abstract: A method for forming a dual damascene opening to protect a low-K dielectric insulating layer including providing a semiconductor process wafer comprising a via opening extending though a thickness portion of at least one dielectric insulating layer; depositing a first dielectric layer stack layer comprising at least one dielectric insulating layer over the at least one dielectric insulating to seal the via opening; blanket depositing a second dielectric layer stack comprising at least one dielectric layer to form a hardmask over and contacting the first dielectric layer stack; photolithographically patterning and etching through a thickness of the hardmask and the first dielectric layer stack to form a trench opening etching pattern overlying and encompassing the via opening while leaving the via opening sealed; and, etching through a thickness portion of the at least one dielectric insulating layer to form a dual damascene opening.

Abstract: A method for forming a dual damascene opening comprising the following steps. A structure having an exposed conductive structure formed therein is provided. An etch stop layer is formed over the structure and the exposed conductive structure. A dielectric layer is formed over the etch stop layer. A hard mask layer is formed over the dielectric layer. The hard mask layer is patterned to form a partially opened hard mask layer. The partially opened hard mask layer having a trench area and a via area. The partially opened hard mask layer within the via area is patterned to form a partial via opened hard mask layer. Simultaneously, the partial via opened hard mask layer within both the trench area and the via area are etched and removed, and the dielectric layer within the via area is partial etched to form a partially opened dielectric layer to: expose a portion of dielectric layer within the trench area; and form a partial via within the partially opened dielectric layer.

Abstract: Low K dielectrics, such as porous silica, present a problem during damascene processing in that the trench floor tends to be rough, thus requiring a thicker than desired barrier layer. This problem has been overcome by fully covering the trench floor with a layer of a flowable material following which an etchant is provided that etches both the trench and flowable materials at approximately the same rate. Using this etchant, the trench floor is then uniformly etched until only a small amount of flowable material remains. After removal of any and all remaining flowable material, it is found that the roughness at the trench floor has been reduced by a factor of about 3-5. This allows a barrier layer of normal thickness to be used during the standard copper damascene process without danger of copper leakage. The process is particularly well suited for use with porous silica dielectrics having a dielectric constant less than about 2.5.