Abstract:
A system for merging product characterization information with a characterized product employs a merging rule database and a product characterization database. A merging processor receives the product characterization information and the merging criteria to create a characterization information result. The characterization information result is created by extracting a trigger merging rule form the merging rule database and determining whether the trigger merging rule has been met to initiate merging the product characterization information with the product. If the products have no characterizations that meet the merging criteria, a union map and an intersection map for the characterized product are created. The merged product characterization information is connected to the product by marking the product to identify it as having met the merging criteria.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates generally to systems and methods for merging product characterization information with a characterized product. More particularly, this invention relates to systems and methods for merging integrated circuit test characterization data with characterized integrated circuit die formed on a semiconductor wafer.  
         [0003]     2. Description of Related Art  
         [0004]     In enterprises such as integrated circuit wafer processing companies commonly referred to as “silicon foundries”, products (integrated circuit die formed on wafers) are tested and the results merged with the products for shipment to the customer. In the example of the integrated circuit wafer, the products (integrated circuit die) may be non-functioning or function at different performance levels. The test information provides characterization data for each integrated circuit die. The test information is used to sort or bin the integrated circuit die when the wafers are scribed to dice the individual integrated circuit die from the wafer.  
         [0005]     Refer now to  FIG. 1  to review the merging of the product test characterization data for products like integrated circuit die on a wafer of the prior art. A wafer  5  is processed to form the integrated circuit die. During and after the processing, the tester  10  characterizes the wafer  5  to provide a parametric and functional description of the operation of the integrated circuit die formed on the wafer  5 . The parametric data maybe voltage versus current curves for active devices to describe DC parameters or the results of ring oscillators to describe AC performance of the wafers. Further, the actual functioning of the integrated circuit die may be determined. The tester  10  creates a circuit probe result file  16  that is maintained by a data retention device  15  such as a magnetic or electro-optical disk.  
         [0006]     The data retention device  15  is in communication  20  with a customer or product engineer  30  through the engineering data analysis system  25 . The engineering data analysis system  15  provides the necessary evaluation to create a yield analysis for each lot of product (wafers)  5  produced. The data retention device  15  is further in communication  37  with the circuit probe server system  35  that provides the control and testing programs for the tester  10 . The circuit probe server system  35  is in communication with a program retention device  40  that contains the control and testing programs for the tester  10 . The program retention device  40  further has a converter program process  50  stored for the conversion of the circuit probe result file  16  to formats desired by the customer  30 . The converter program process  50  is constructed of multiple product characterization data converters  51 ,  52 ,  53 , and  54  that retrieve the circuit probe result file for a product associated with the individual product characterization data converters  51 ,  52 ,  53 , and  54  to generate a merged circuit probe result file  46  that is retained by the data retention device  45 . The data retention device  46  is in communication  55  with the engineering data analysis system  25  to provide the merged result circuit probe file  46  for the yield analysis. The data retention device is also in communication  46  to a wafer ink probe  60  which marks the wafer  65  with the necessary binning and yield information. This is effectively the merging of the product with the product characterization data for use by the customer to determine the appropriate binning and yield of the product (wafer)  65 .  
         [0007]     All of the product characterization data converters  51 ,  52 ,  53 , and  54  are constructed based on product (wafer)  5  descriptions, since each product type is unique and may have differing merging rules. This structure is not conducive to real-time processing of the product characterization data result file  16  for merging with the product and thus must be executed on a batch basis. In products such a dynamic random access memory (DRAM), the product may have a failure on its first test and characterization by the tester  10  and then be repaired. Upon its repair, the DRAM wafer is then retested and the merging of the product characterization data must be based on the results of two test and characterization operations. Again, this does not permit real-time processing of the merging of the characterization data with the product.  
         [0008]     U.S. Pat. No. 6,049,803 (Szalwinski) describes a method for interactive documentation of a database framework and data continued in a relational database, such as, an engineering database with data related to the manufacturing and testing of semiconductor devices. Multiple documentation levels are provided such that each documentation level includes a view of the database framework with at least one documentation level including a high level view of the database framework. The documentation levels include descriptions and definitions of the views of the database framework, and the views of the database framework include descriptions and definitions of entities, attributes and schema of the data in the database. One documentation level is displayed that includes the view of the database framework. User selectable items are displayed on the display device at each documentation level. The user selectable items represent other documentation levels or other views of the database framework. The other documentation levels are accessed by actuating one of the user selectable items. The documentation levels and the views of the database framework are based on one or more driving tables included in the database. The driving tables can be modified or updated; thereby modifying or updating the documentation levels and the views of the database framework.  
         [0009]     U.S. Pat. No. 5,841,893 (Ishikawa, et al.) provides data analysis stations respectively for a probing tester and an automatic particle inspection machine. In the data analysis station, the coordinates on which the disposition of the die are described on a product basis are equal to those on which the locations of the defects are described. Further, the station provides a function to determine which of the die have the defects. These data analysis stations are connected through a communication line. The data is analyzed on a dice basis, resulting in being able to grasp the relationship between how the defects are caused and the product character of the dice.  
         [0010]     U.S. Pat. No. 5,761,064 (La, et al.) teaches an automated wafer defect management system in which wafer defect data is collected from wafer inspection instruments. The wafer defect data is converted into a standard data format and made available through a central database system to workstations for review, analysis, and evaluation.  
         [0011]     U.S. Pat. No. 6,434,725 (Sommer, et al.) describes a method and system for semiconductor testing using yield correlations between global and class parameters for semiconductor die. The system and method provide for including test data for multiple tests on each of multiple die. A global parameter is assigned to each dice as a quality measure based on the test data for that dice. Values for parameter classes are determined where each parameter class represents a parameter measured for each dice tested. A correlation between the values of the parameter classes and the global parameter values for the die are then determined. The correlation for each of the parameter classes is compared to identify at least one parameter class that detracts from dice yield.  
       SUMMARY OF THE INVENTION  
       [0012]     An object of this invention is to provide a system and method for merging product characterization information with a characterized product.  
         [0013]     Another object of this invention is to provide a system and method for merging product characterization information with a characterized product where rules governing this merging are retained in a rule database.  
         [0014]     To accomplish at least one of these objects, a system for merging product characterization information with a characterized product has a product characterization database which is in communication with a product characterizing device to receive the product characterization information for the characterized product. In a preferred embodiment of this invention, the characterized product is wafers with integrated circuit die formed. The characterizing device is a test system that provides parametric and functional tests of the integrated circuit die formed on the wafer.  
         [0015]     The system includes a merging rule database that describes a criteria for merging the product characterization information with the characterized product. In the case of an integrated circuit wafer, the merging criteria is determined by the results from tests performed by the tester and the sorting or binning of the integrated circuit die.  
         [0016]     A merging processor is in communication with the product characterization database to receive the product characterization information and the merging rule database to receive the merging criteria to create a characterization information result. The characterization information result is created by first extracting a trigger merging rule form the merging rule database and determining whether the trigger merging rule has been met to initiate a merging of the product characterization information with the product. If the trigger merging rule has been met, a merging criteria sort type map and a merging criteria sort number map are extracted. The merging criteria sort type map determines which of the products has certain characteristics and the merging criteria sort number map determines which of the products is classified according to grades of the merging criteria. A merged product characterization information is created as defined by the grades of the merging criteria.  
         [0017]     If the products have no characterization that meets the merging criteria, a union map and an intersection map for the characterized product are created. The union map is formed by identifying the characterized product that meets at least one of a plurality of sub-criteria of the merging criteria. The intersection map is formed by identifying the characterized product that meets all of the plurality of sub-criteria of the merging criteria. The merged product characterization information is created according to the union map.  
         [0018]     If the union map and the intersection map indicate that too many of the characterized products do not meet the merging criteria, an error handling process is initiated.  
         [0019]     The merged product characterization information is connected to the product by marking the product to identify it as having met the merging criteria. In an integrated circuit die formed on a wafer, the binning results are marked on each integrated circuit dice meeting certain criteria described in the merging data.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a system diagram of a computer integrated manufacturing system for merging product characterization information data with a product of the prior art.  
         [0021]      FIG. 2  is a system diagram of a computer integrated manufacturing system for merging product characterization information data with a product of this invention.  
         [0022]      FIG. 3  is a diagram of the structure of the product characterization information data rule merging database of Fig. of this invention.  
         [0023]      FIGS. 4   a  and  4   b  are flow charts of the process for merging of the product characterization information data with a product of this invention.  
         [0024]      FIGS. 5   a - 5   d  are illustrations of the types of merging methods employed to determine the product characterization information data to be merged with the product of this invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     A computer integrated manufacturing system of this invention retrieves product characterization information data from a characterization device such as an integrated circuit probe tester. A merging processor receives the product characterization information data and extracts merging criteria from a merging rule database. The merging processor merges the product characterization information data according to the merging criteria to create merged result characterization information data. This merged result characterization information data is then combined with the product and delivered to the customer. The merging criteria is developed from a union and/or an intersection of a mapping of the product characterization information data for multiple tests. A product may be tested then repaired and then tested again. The first testing results and the second testing results are used to form a union of a mapping of the results to provide the total characterization of the product. Alternately, a given product may have been tested and repaired, but some of that product was unrepairable and some other product has failed in a second testing, the intersection of a mapping of the first testing and the second testing determines whether that product has been lost or failed. Further, the merging criteria maybe a particular sort mapping developed by the customer, where the product is sorted into categories or bins dependent upon the results of the product characterization information data.  
         [0026]     Refer now to  FIG. 2  for a discussion of the merging of the product test characterization data for products like integrated circuit die on a wafer of this invention. A wafer  105  is processed to form the integrated circuit die. During and after the processing, the tester  110  characterizes the wafer  105  to provide a parametric and functional description of the operation of the integrated circuit die formed on the wafer  105 . The parametric data maybe voltage versus current curves for active devices to describe DC parameters or the results of ring oscillators to describe AC performance of the wafers. Further, the actual functioning of the integrated circuit die maybe determined. The tester  110  creates a circuit probe result file  116  that is maintained by a data retention device  115  such as a magnetic or electro-optical disk. The circuit probe result file  116  provides the product test characterization information data.  
         [0027]     The data retention device  115  is in communication  137  with the circuit probe server system  135  to transfer the circuit probe result file  116  to the circuit probe server system  135 . The circuit probe server system  135  is connected to a program retention device (not shown) which contains the control and testing programs for the tester  110 . The circuit probe server system  135  retrieves the control and testing programs for the tester  110 .  
         [0028]     A merging criteria rule database  140  is connected to the circuit probe server system  135  to provide the criteria for merging the circuit probe result file  116  to the wafer  105  for transfer to the customer. The merging criteria rule database  140 , as shown in  FIG. 3 , contains a trigger part number  205  which identifies the part number of the wafer  105  that has the merged product characterization information data. The merge sort number  210  provides an identification number for the merging rules to be applied to the integrated circuit die formed on the wafer  105 . The maximum number of sorting categories or bins for which there are no integrated circuit die on the wafer  105  (NA Max Count)  215  is a limit which when exceeded causes an error message in the merging process. The rule sequence  220  provides the order the merging criteria or rules  225  are to be applied to the sorting of the integrated circuit die of the wafer  105 . The merging criteria rules  225  are defined as follows: 
        $% (“%” is an integer) indicates a Sort bin number (i.e. %1 is Sort 1, %2 is Sort 2 . . . ).     $G indicates Sort good bin. A bin into which fully functional die are assigned.     $O indicates Sort open bin. A bin into which die having open or short circuits are assigned     $R indicates Sort repairable bin. A bin into which failing but repairable die are assigned     $B indicates Sort bad bin. A bin into which non-repairable die are assigned.     $NA indicates that there isn&#39;t any bin on the coordinates. A default bin for die that may have not been tested or for which the tester  110  malfunctioned.     * indicates “don&#39;t care what bin it is”—a wild card.        
 
         [0036]     The trigger sort number  230  defines the sorted category or bin number that is to be sorted and the merge bin definition file  235  is the identification of the file which is to be used for the resulting merged product characterization information data. The trigger bin definition file designator  240  defines the file for the product (wafer)  105 , the tester type, the sorting parameter designator, and the version of the testing program. The trigger bin definition file designator  240  contains the characterization data for the sorting of the integrated circuit die of the wafer  105 . The input sort list  245  provides the sort category or bin definitions that are to be merged and the resulting binning definition of the merge. The input notch list  250  provides an orientation description for the designation of the mapping information of the product test characterization data. A wafer  105  has a notch or some other orientation designator. This input notch list  250  details the orientation of the notch and the quadrant description of the wafer to detail the designation of the integrated circuit die for mapping the product test characterization data.  
         [0037]     The circuit probe server system  135  performs a program process that is retained on a program retention device connected to the circuit probe server system  135 . The program process, when executed, performs the circuit probe server automatic merging process  150  upon the product test characterization data from a circuit probe result file  116  based on the rules from the product test characterization data from the merging criteria rule database  140 . The circuit probe server automatic merging process  150  is shown in  FIGS. 4   a  and  4   b . The circuit probe server system  135  reads (Box  300 ) the product test characterization data (CP Result File)  116  from the data retention device  115  and creates (Box  305 ) a merged result product test characterization data (Merged CP Result File)  146  to the data retention device  145 . The trigger part number  205  of the merging criteria rule database  140  is queried (Box  310 ) to determine whether the part number of the product (wafer)  105  requires a merging sort of the product test characterization data (CP Result File)  116 . If not, the process is ended (Box  315 ).  
         [0038]     If a merging sort is required, the sort bin type mapping and the sort bin number mapping is extracted (Box  320 ) from the product test characterization data (CP Result File)  116 .  
         [0039]     The merging criteria rules  225  of the merging criteria rule database  140  as shown in  FIG. 3  are compared (Box  325 ) to the sort bin type mapping and the sort bin number mapping to determine whether there are bins for which die may have not been tested or for which the tester  110  malfunctioned ($NA). If there are no such bins, the sorting rule sequence  220 , the sorting rules  225  the trigger sort number  230  and the trigger bin definition file designator  240  are extracted from the merging criteria rule database  140 . The sort bin type map and the sort bin number map are evaluated according to the sorting rules  225  to create (Box  330 ) the merged result product test characterization data (Merged CP Result File)  146 .  FIG. 5   d  illustrates a form of the sorting rules. In this instance, a wafer is tested by two separate parametric and/or functional criteria (i.e. frequency of operation). The wafer is mapped into a first sort map  400  and a second sort map  405 . The customer establishes the trigger sort map  425 . In this case, the customer has determined that the die must have passed the sort criteria for both the first sort map  400  and the second sort map  405  or at least the second sort map  405 . This means that the merged characterization data must include the die  427  and the die  429  in the merging of the product test characterization data (CP Result File)  116 .  
         [0040]     The sort bin type mapping and the sort bin number mapping are tested (Box  335 ) to determine if the total wafer  105  has been merged. If total wafer  105  has been merged, the merged result product test characterization data (Merged CP Result File)  146  is read (Box  340 ) from a temporary working data retention area and written (Box  345 ) to the data retention device  145 . If the total wafer  105  has not been merged, there is an error in the definition of the sort bin type mapping and the sort bin number mapping and an error handling procedure is initiated (Box  370 ).  
         [0041]     When the merging criteria rules  225  are compared (Box  325 ) to the sort bin type mapping and the sort bin number mapping and there are bins for which die may not have been tested or for which the tester  110  malfunctioned ($NA), a union map and an intersection map with the results of the testing to the merging criteria or sort bins is created (Boxes  350  and  355 ). Refer to  FIGS. 5   a  and  5   b  for a discussion of the union map and the intersection map.  FIG. 5   a  illustrates a union of the results from testing the two sorted bins. A wafer is tested by two separate parametric and/or functional criteria (i.e. frequency of operation). The wafer is mapped onto a first sort map  400  and a second sort map  405 . Those die that pass the criteria of the first sort are identified  402  on the first sort map  400  and those die that pass the second sort are identified  406  on the second sort map  405 . The union map  410  is created (Box  350 ) with those die  412  that have passed the criteria of the first sort test and the second sort test, and those die  413  that have passed the first sort test, and those die  414  that have passed the second sort test.  FIG. 5   b  illustrates the intersection of the results of testing for the two sorted bins. In the illustration, the wafer is again mapped onto the first sort map  400  and the second sort map  405 . In this instance, the intersection map  415  is created (Box  355 ) as only those die  417  that have passed the criteria of the first and second sort tests inclusively.  
         [0042]     The merging criteria rule database  140  is examined to determine the number of sorting categories or bins for which there are no integrated circuit die on the wafer  105  (NA Max Count)  215 . The intersection map is subtracted from the union map to determine the number of sorting categories or bins for which there are no integrated circuit die on the wafer  105 . The subtraction is illustrated in the subtraction map  420  of  FIG. 5   c . The union map  410  and the intersection map  415  are subtracted such that those die that have exclusively passed the criteria of either sort 1 (die  424 ) or sort 2 (die  422 ) are identified. In the case of a DRAM this would represent die that had not passed the criteria of sort 1 had been repaired and had passed the criteria of the sort 2. These die  422  and  424  are considered to have no binning available resulting from the merging.  
         [0043]     These results of the subtraction are compared (Box  360 ) to the maximum number of sorting categories or bins for which there are no integrated circuit die on the wafer  105  (NA Max Count)  215  of the merging criteria rule database  140 . If the results of the subtraction exceeds the maximum number of sorting categories or bins for which there are no integrated circuit die on the wafer  105  (NA Max Count)  215 , the error handling procedure is initiated (Box  370 ). If the subtraction is not excessive, the merged result product test characterization data (Merged CP Result File)  146  is created (Box  365 ). The merged result product test characterization data (Merged CP Result File)  146  is read (Box  340 ) from a temporary working data retention area and written (Box  345 ) to the data retention device  145 .  
         [0044]     Returning now to  FIG. 2 , the product test characterization data (Merged CP Result File)  116  is transferred to be combined with the product (wafer  105 ) in this instance a wafer ink probe  160 . The wafer ink probe  160  marks the wafer  105  to identify those die that have met the criteria of the testing or are to be sorted to specific bins based on their parametric and function testing. The marked wafer  165 , which has now been combined with the merged product test characterization data, is transferred to the customer.  
         [0045]     While this invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.