Methods for making reinforced wafer polishing pads and apparatuses implementing the same

#1. Field of the Invention

#The present invention relates to chemical mechanical polishing (CMP) techniques and, more particularly, to the efficient, cost effective, and improved CMP operations.

#2. Description of the Related Art

#The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements.

#FIG. 1A shows a linear polishing apparatus which is typically utilized in a CMP system.

#FIG. 1B shows a side view of the linear polishing apparatus.

#An invention for a method of making a polishing pad structure and an apparatus using the same is disclosed. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be understood, however, by one of ordinary skill in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.

#In general terms, the present invention is directed toward a polishing pad structure and method for making the structure. The polishing pad structure includes a supporting layer, a cushioning layer, and a pad layer. In a preferred embodiment, the pad layer is designed and made as a contiguous and seamless unit and is preferably adhered to the cushioning layer to enable more consistent and effective wafer polishing during CMP operations. The pad layer, being a contiguous and seamless unit also provides for a longer lasting pad structure that is substantially more resistant to delamination.

#As described herein, a polishing pad structure may include a polishing pad (or pad layer) in addition to any other layer that may utilized in conjunction with the polishing pad such as, for example, the cushioning layer, the support layer, a reinforcement layer, a polymeric precursor layer, a polymeric precursor, a liquid polymeric precursor layer, etc. In a preferred embodiment, the support layer is a stainless steel belt. The polishing pad within a polishing pad structure may be in either a generic pad form, a belt form, or any other form that may be utilized in a CMP process. The polishing pad may also be referred to as a seamless polymeric polishing pad, a seamless polymeric polishing belt, polymeric polishing pad, a linear belt polymeric polishing pad, polymeric polishing belt, a polishing layer, a polishing belt or any other term that could describe the present invention. Furthermore, the polishing pad structure of the present invention may be utilized in any type of operation which may require controlled, efficient, and accurate polishing of any surface of any type of material. One embodiment of the polishing pad structure as described below includes two basic structural components: a seamless polymeric polishing pad, and a base belt. The base belt, as used herein includes at least one cushioning layer, and a reinforcement layer such as the aforementioned stainless steel belt. The seamless polymeric polishing pad is attached to the base belt by an adhesive film. By using a seamless polishing pad, the risk of moisture induced weaknesses and the resulting delamination prevalent in the prior art may be reduced thus increasing polishing pad life. In addition, the base belt increases wafer polishing effectiveness. Therefore, the apparatus and method of polishing wafers optimizes CMP effectiveness and increases wafer processing throughput by way of an apparatus with a seamless polymeric polishing pad and a unique combination of a reinforcement layer and a cushioning layer.