Abstract:
According to an example embodiment, the present invention comprises a CMP pad conditioner arrangement. An inlet is configured and arranged for receiving treatment elements. A distribution surface is coupled to the inlet and is configured and arranged to disperse the treatment elements. A multitude of outlets are coupled to the distribution surface and are configured and arranged to dispense the treatment elements onto a CMP pad. Benefits of using this embodiment include enhanced pad cleaning, better slurry dispense, improved wafer quality, and faster production.

Description:
FIELD OF THE INVENTION 
     The present device relates generally to semiconductor devices and their fabrication and, more particularly, to semiconductor devices and tools for their manufacture involving chemical-mechanical polishing (CMP). 
     BACKGROUND OF THE INVENTION 
     The electronics industry continues to rely upon advances in semiconductor manufacturing technology to realize higher-functioning devices while improving reliability and cost. For many applications, the manufacture of such devices is complex, and maintaining cost-effective manufacturing processes while concurrently maintaining or improving product quality is difficult to accomplish. As the requirements for device performance and cost become more demanding, realizing a successful manufacturing process becomes more difficult. 
     A byproduct of the increased complexity of semiconductor devices includes uneven device surfaces, which become more prominent as additional levels are added to multilevel-interconnection schemes and circuit features are scaled to submicron dimensions. Typically, each level within the device is patterned, resulting in a surface with varied “step-heights” where metal forming the pattern remains on the surface. 
     Planarization is a term describing the surface geometry of a semiconductor device. Complete planarization occurs when the surface of the dielectric is flat, as in a plane. No planarization occurs when the surface of the dielectric directly models the “step-height” surface of the metal pattern in the layer underneath. The degree of planarization refers to the degree to which the varied surface geometry can be “planarized,” or smoothed out into a planar surface. Varied surface geometry is often undesirable. Therefore, as additional layers are formed within devices, the required degree of planarization increases. 
     A commonly used new planarization process in semiconductor device manufacturing is chemical-mechanical polishing, or CMP. CMP is useful in the planarization of silicon wafers and of VLSI circuits between different manufacturing processes. CMP is a popular planarization method, due in part to its usefulness in the global planarization of semiconductor devices. Traditional planarization processes are restricted to effecting local planarity or topographical variation on a small scale, whereas CMP is often useful on a global scale greater than ten microns. 
     In one application, a CMP process involves securing a semiconductor wafer to a wafer holder with the wafer located face-down on a polish pad. Both the polish pad and the wafer holder rotate. A slurry, typically a colloidal silica that is a suspension of SiO 2  particles, is applied to the process. The particle size typically varies from 100 angstroms to 3 microns. The slurry is generally applied using a wand feeding to the wafer holder and pad. The rate of removal of material from the wafer is a combination of chemical and mechanical rates. The mechanical removal rate is roughly proportional to the pressure and the relative velocity of the wafer. The chemical removal rate is a function of the size of the slurry particles and the solution pH, wherein the maximum removal rate is generally obtained using a slurry having a pH of about 11.5. 
     In addition to the use of slurry in the CMP process, a conditioner is also typically used for conditioning the polish pad. The conditioner aids in the CMP polishing process and contributes to the longevity of the pad. Another need in the CMP process is for adequately and efficiently cleaning the pad and the wafer itself. In clean room environments, it is important to maintain a CMP process that produces as few contaminants as possible. Since the slurry particle size ranges in the sub-3 micron range, clean-up is difficult and thus of high importance. In addition, it is helpful to prevent the byproduct resulting from the polishing of each wafer from accumulating on the pad and reaching additional wafers. 
     The traditional method for conditioning the pad and dispensing slurry is to use two separate mechanical components: a slurry dispense wand and a pad conditioner assembly. There are disadvantages in using two separate components. For instance, the slurry cannot be spread uniformly across the pad and may accumulate in the pad conditioning head. The non-uniform distribution of slurry distribution hinders the polishing process. In addition, the reaction byproduct cannot be thoroughly removed from the pad. When more than one wafer is processed at once, inadequate cleaning of the pad results in the reaction byproduct and other materials from one wafer coming into contact with other wafers. These disadvantages may result in, for example, long arc style scratches, shallow micro-scratches, inter-die thickness variation, and residual slurry particles. These disadvantages ultimately result in a significant yield lost and in reliability problems due in part to possible metal stringers in the shallow scratch area and surrounding residual slurry particles. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a method and apparatus for improving the CMP process, the improvements including but not limited to enhanced pad cleaning and conditioning, better slurry dispense, improved wafer quality, and faster production. The present invention is exemplified in a number of implementations and applications, some of which are summarized below. 
     According to an example embodiment, the present invention comprises a CMP pad conditioner arrangement. The arrangement includes an inlet for receiving treatment elements. A distribution surface is coupled to the inlet and is configured and arranged to uniformly disperse the treatment elements. A multitude of outlets are coupled to the distribution surface and are configured and arranged to dispense the treatment elements onto the CMP pad. 
     According to another example embodiment, the present invention is directed to a CMP polishing machine. The machine includes the pad conditioner arrangement described in the preceding paragraph. 
     The invention is directed to a CMP pad conditioner arrangement, according to another example embodiment. The arrangement comprises means for receiving treatment elements, means for distributing treatment elements, and means for conditioning the pad. 
     According to still another example embodiment, the present invention is directed to a method for conditioning a CMP pad using a conditioner apparatus having an inlet, a distribution surface coupled to the inlet, and a multitude of outlets. Treatment elements are supplied to the apparatus via the inlet. The treatment elements are dispersed and distributed via the distribution surface onto the CMP pad via the multitude of outlets. 
     The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and detailed description which follow more particularly exemplify these embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may be more completely understood in consideration of the following detailed description in connection with the accompanying drawings, in which: 
     FIG. 1A shows a top view of a first CMP pad conditioner arrangement, according to an example embodiment of the present invention; 
     FIG. 1B shows a side view of a first CMP pad conditioner arangement, according to an example embodiment of the present invention; 
     FIG. 2A shows a top view of a second CMP pad conditioner arrangement, according to another example embodiment of the present invention; 
     FIG. 2B shows a side view of a second CMP pad conditioner arrangement; according to another example embodiment of the present invention; 
     FIG. 3A shows a top view of a third CMP pad conditioner arrangement, according to another example embodiment of the present invention; and 
     FIG. 3B shows a side view of a third CMP pad conditioner arrangement, according to another example embodiment of the present invention. 
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     According to an example embodiment, the present invention is directed to an arrangement for use in a CMP process. The arrangement includes capabilities for receiving, dispersing, and dispensing treatment elements, as well as for conditioning the CMP pad. In addition, the arrangement may also include the capability of rotation. The conditioning of the pad may include, for example, removing deposits, roughing the pad, or other preparations for use in the CMP process. The arrangement includes an inlet port for receiving treatment elements. A distribution surface is coupled to the inlet port and is configured and arranged to disperse the treatment elements. A multitude of outlet ports are coupled to the distribution surface and are configured and arranged to dispense the treatment elements onto the CMP pad. 
     FIG. 1A shows a top and FIG. 1B a side view of a CMP pad conditioner arrangement  100  for use in a CMP process, according to another embodiment of the present invention. Both FIGS. 1A and 1B use the same reference numbers to correspond to the same aspects shown in each figure. Supply  130  is configured and arranged to supply treatment elements to the pad conditioner head  140 . Pad conditioner head  140  includes holes  110  for dispensing treatment elements to the surface to be conditioned. Brushes  120  are coupled to the pad conditioner head  140 . The brushes may, for instance, comprise chemically resistant material, such as plastic or Teflon. The use of chemically resistant brushes is particularly advantageous in applications where the treatment elements include chemicals that are reactive with non-chemically resistant brush material. 
     According to another example embodiment, a method for conditioning a CMP pad is provided. Referring again to FIGS. 1A and 1B, supply  130  is coupled to pad conditioner head  140 . Treatment elements are delivered to the pad conditioner head  140  by way of supply  130 . The treatment elements may include, for example, chemicals ranging in pH from highly basic to highly acidic, or solvents such as de-ionized (DI) water. The treatment elements are dispersed in the head  140 , and dispensed through holes  110 . Brushes  120  are coupled to pad conditioner head  140 , and are caused to contact a CMP pad. The treatment elements are dispersed onto the CMP pad, and the CMP pad is conditioned. Conditioning the CMP pad may, for instance, also include rotating the pad conditioner head  140 , in a manner such as rotating about its center. 
     FIG. 2A shows a top and FIG. 2B shows a side view of a CMP pad conditioner arrangement  200  for use in a CMP process, according to another example embodiment of the present invention. Both FIGS. 2A and 2B use the same reference numbers to correspond to the same aspects shown in each figure. Supply  230  is configured and arranged to supply treatment elements to the pad conditioner head  240 . Pad conditioner head  240  includes holes  210 , for dispensing treatment elements to the surface to be conditioned. Grid arrangement  220  is coupled to the pad conditioner head  240 . For instance, grid arrangement  220  may include material such as diamond or CVD diamond coated with Ni. 
     According to yet another example embodiment, a method for conditioning a CMP pad is provided. Referring again to FIGS. 2A and 2B, supply  230  is coupled to pad conditioner head  240 . Treatment elements are delivered to the pad conditioner head  240  by way of supply  230 . The treatment elements are dispersed in the head  240 , and dispensed through holes  210 . Grid arrangement  220  is coupled to pad conditioner head  240 , and is caused to contact a CMP pad. The treatment elements are dispersed onto the CMP pad, and the CMP pad is conditioned. Conditioning the CMP pad may, for instance, also include rotating the pad conditioner head  240 , in a manner such as rotating about its center using a motor/axle arrangement (not shown) coupled to the housing for the supply  230  (or  130 ). 
     FIG. 3A shows a top and FIG. 3B shows a side view of a CMP pad conditioner arrangement  300  for cleaning a pad in a CMP process, according to another example embodiment of the present invention. Both FIGS. 3A and 3B use the same reference numbers to correspond to the same aspects shown in each figure. Treatment element supplies  350  and  360  are configured and arranged to supply elements to supply  330 . Supply  330  is configured and arranged to supply treatment elements to the pad conditioner head  340 . Pad conditioner head  340  includes holes  310 , for dispensing treatment elements to the surface to be conditioned. Brushes  320  are coupled to the pad conditioner head  340 . 
     According to another example embodiment, a method for conditioning a CMP pad is provided. Referring again to FIGS. 3A and 3B, treatment element supplies  350  and  360  are coupled to supply  330 . Supply  330  is coupled to pad conditioner head  340 . Treatment elements are delivered to pad conditioner head  340  by way of supply  330 . The treatment elements are dispersed in the head  340 , and dispensed through holes  310 . Brush arrangement  320  is coupled to pad conditioner head  340 , and is caused to contact a CMP pad. The treatment elements are dispersed onto the CMP pad, and the CMP pad is conditioned. Conditioning the CMP pad may, for instance, also include rotating the pad conditioner head  340 , in a manner such as rotating about its center. 
     Treatment element supplies  350  and  360  may be used to supply several different elements. For instance, one supply may be used to supply chemicals, and the other used to supply DI water. In an example embodiment, pad conditioner arrangement  300  is used in connection with a metal polish process, in which the chemical supply includes a low pH chemical. In another example embodiment, pad conditioner arrangement  300  is used in an oxide polish process, in which the chemical supply includes a high pH chemical, such as, for example, a chemical having a pH of about 11.5. 
     Skilled artisans will recognize that the above-discussed example embodiments may be implemented by modifying commercially-available equipment. Examples of such equipment include MIRRA and 6DS SP, respectively manufactured by Applied Material and Strausbough. 
     While the present invention has been described with reference to several particular example embodiments, those skilled in the art will recognize that many changes may be made thereto. For example, many features of the above embodiments are combinable in a single conditioner arrangement and/or conditioning process. Such changes do not depart from the spirit and scope of the present invention, which is set forth in the following claims.