Abstract:
A system and method is provided that facilitates the uniform development of a pattern on a photoresist material layer using a developer. The present invention accomplishes this end by considering the acid-base relationship of the photoresist material and developer and monitoring the development of water formed in the development process. Typically, photoresist material is purchased or manufactured with known concentrations of resin and photoacid generator. Therefore, by monitoring the development of water in the development process, the present invention can measure the acid consumption in the development process. The present invention can then utilize this information in optimizing the developer volume, developer concentration and developer time to improve the quality of the developed image pattern on the photoresist material layer.

Description:
TECHNICAL FIELD 
     The present invention generally relates to semiconductor processing, and in particular to a system for optimal development of a photoresist material layer on a wafer. 
     BACKGROUND OF THE INVENTION 
     In the semiconductor industry, there is a continuing trend toward higher device densities. To achieve these high densities there has been and continues to be efforts toward scaling down device dimensions (e.g., at submicron levels) on semiconductor wafers. In order to accomplish such high device packing density, smaller and smaller features sizes are required. This may include the width and spacing of interconnecting lines, spacing and diameter of contact holes, and the surface geometry such as corners and edges of various features. 
     The requirement of small features with close spacing between adjacent features requires high resolution photolithographic processes. In general, lithography refers to processes for pattern transfer between various media. It is a technique used for integrated circuit fabrication in which a silicon structure or wafer is coated uniformly with a radiation-sensitive film, the resist, and an exposing source (such as optical light, x-rays, or an electron beam) illuminates selected areas of the surface through an intervening master template, the mask, for a particular pattern. The lithographic coating or resist is generally a radiation-sensitive coating suitable for receiving a projected image of the subject pattern. 
     The resist can be classified into a positive type resist or a negative type resist based on the type of reaction, and a two component or a three component type based on the number of components in the resist. A positive type resist becomes more soluble in an aqueous based developer when exposed to radiation and negative type resist becomes less soluble in an aqueous based developer when exposed to radiation. A two component type includes a base resin, such as a photosensistive organic compound and a photoacid generator. A photoacid generator is a compound that is neutral, but which decomposes to form an acid upon exposure to light energy at particular wavelengths or frequencies. The photosensitive organic compound is a compound that absorbs light at different wavelengths and thereafter transfers energy to the photoacid generator to form the acid. A three component type includes a base resin, a photoacid generator and an acid-crosslinking agent. Exposure of the resist through a photomask causes the image area to become either more or less soluble (depending on the coating) in a particular solvent developer. The solvent is a base and the more soluble areas of the resist are removed in the developing process to leave the pattern image in the coating. The patterned image is used as a mask for etching the pattern into the wafer. The resist is then stripped from the wafer leaving the patterned image etched into the wafer. 
     Application of the resist onto the wafer is typically accomplished by using a spin coater. The spin coater is essentially a vacuum chuck rotated by a motor. The wafer is vacuum held onto the spin chuck. Typically, a nozzle supplies a predetermined amount of resist to a center area of the wafer. The wafer is then accelerated to and rotated at a certain speed, and centrifugal forces exerted on the resist cause the resist to disperse over the whole surface of the wafer. After the resist is spin coated and selectively irradiated to define a predetermined pattern, the irradiated or nonirradiated portions are removed by applying a developer. The developer is also spin coated onto the wafer by applying developer across the resist and then spin coating the developer until centrifugal forces disperse the developer over the coating of resist. After a predetermined time, the photoresist material layer becomes developed and the irradiated or nonirradiated portions are removed by rinsing or washing with a washing solution material. 
     However, the rate of development may vary based on the amount and concentration of the photoacid generator in the resist, the identity of the photoacid generated, the identity of the developer, the concentration and volume of the developer and the amount of time that the resist is exposed to the developer. Failure to use the appropriate amount/concentration of developer and/or appropriate exposure time for a given photoacid generator and developer results in nonuniform quality of the imaged pattern across the resist and ultimately wafer defects. 
     In view of the above, a system/method is needed, for dispensing an optimal volume and concentration of developer across a photoresist material layer formed on a wafer for an optimal period of development time. 
     SUMMARY OF THE INVENTION 
     The present invention provides for a system and method that facilitates the uniform development of a pattern on a photoresist material layer using a developer. The present invention accomplishes this end by considering the acid-base relationship of the photoresist material and developer and monitoring the development of water formed in the development process. Typically, photoresist material is purchased or manufactured with known concentrations of resin and photoacid generator. Therefore, by monitoring the development of acid or formation of water in the development process, the present invention can measure the acid consumption in the development process. The present invention can then utilize this information in optimizing the developer volume, developer concentration and development time to improve the quality of the developed image pattern on the photoresist material layer. 
     A developer plate can be employed forming a parallel plate pair with the wafer during application of the developer. The developer plate is disposed in very close proximity with respect to the wafer, such that the developer is squeezed between the two plates thereby spreading evenly the developer over the wafer. Since the developer film is stagnant, the transport of acid into base can be monitored and therefore, the development process can be monitored. Furthermore, the proximity of the developer plate to the wafer during application and the size of a plurality of apertures in the developer plate provides for improved localization with respect to development of the photoresist material layer. 
     In one aspect of the invention, a monitoring or measurement system is provided that measures the amount of water formed in a development process of a photoresist material. The measuring can be accomplished utilizing various techniques. For example, the measuring may be conducted on a test or reference wafer off-line utilizing conventional lab measuring techniques. Using the measured results, adjustments can be made to the developer volume, developer concentration and/or development time until an optimal result is achieved. The measuring may be accomplished by employing in situ laser scattering or laser doppler anemometry techniques. Additionally, the measuring may be accomplished by employing light scattering techniques, such as interferometry and spectrometry. The laser scattering and light scattering techniques can be employed in providing a close loop system, such as a control system for continuously improving the acid consumption of the development process. 
     One particular aspect of the invention relates to a method of developing a selectively irradiated photoresist material layer disposed on a semiconductor wafer. The method includes contacting the photoresist material layer with a volume of developer having a concentration for a period of time whereby the developer and an acid in the photoresist material layer interact to generate an amount of water, measuring the amount of water, determining an amount of acid consumption based on the amount of water measured and adjusting at least one of the developer volume, concentration and contact time based on the amount of acid consumption determined. 
     Another aspect of the invention relates to a system for monitoring development of a selectively irradiated photoresist material layer. The system includes at least one light source disposed near the selectively irradiated photoresist material layer where the at least one light source is adapted to transmit a ray of light across the selectively irradiated photoresist material layer. The system also includes at least one detector disposed near the selectively irradiated photoresist material layer where the at least one detector is adapted to receive a reflected ray of light due to the at least one light source and provide a signal corresponding to the intensity of the reflected ray of light. The system further includes a measuring system operably coupled to the at least one detector where the measuring system is adapted to receive the signal corresponding to the intensity of the ray of light and convert the signal to digital data. A processor is operatively coupled to the measuring system. The processor is adapted to receive the digital data from the measuring system and analyze the digital data wherein the difference of the intensity of the ray of light from the at least one light source to when it is received by at least one detector is proportional to an amount of water generated across the selectively irradiated photoresist material layer due to an interaction of a developer and an acid in the selectively irradiated photoresist material layer. 
     In yet another aspect of the invention, a system of controlling development of a selectively irradiated photoresist material layer is provided. The system includes a nozzle adapted to contact the selectively irradiated photoresist material layer with a volume of developer having a concentration for a period of time, a measuring system adapted to measure an amount of water generated on the selectively irradiated photoresist material layer due to an interaction of the developer and an acid in the selectively irradiated photoresist material layer and a processor operatively coupled to the measuring system and a developer volume and concentration control system. The processor receives data from the measuring system relating to the amount of water measured and the processor uses the data to determine an amount of acid consumption of the selectively irradiated photoresist material layer. The processor is further adapted to provide adjustment information to the developer volume and concentration control system for adjusting at least one of a developer volume, a developer concentration and a developer contact time, so that a subsequent selectively irradiated photoresist material layer having a more uniform development can be achieved. 
     In another aspect of the invention, a system of developing a selectively irradiated photoresist material layer disposed on a semiconductor wafer is provided. 
     The system includes means for applying a developer to the selectively irradiated photoresist material layer, means for measuring an amount of water generated on the selectively irradiated photoresist material layer due to an interaction of the developer and an acid in the selectively irradiated photoresist material layer and means for determining an amount of acid consumption of the selectively irradiated photoresist material layer based on the amount of water measured. 
     To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a  is a flow diagram illustrating one specific methodology for carrying out the present invention; 
     FIG. 1 b  is a bottom view of a developer application system in accordance with one particular aspect of the present invention; 
     FIG. 1 c  is a front view of the developer application system of FIG. 1 b  during application of developer on a wafer in accordance with one particular aspect of the present invention; 
     FIG. 2 a  is a representative schematic block diagram of a monitoring system in accordance with one particular aspect of the present invention; 
     FIG. 2 b  is a representative schematic block diagram of an alternate monitoring system in accordance with one particular aspect of the present invention; 
     FIG. 3 is a flow diagram illustrating one specific methodology for carrying out the monitoring system of FIG. 2 a  in accordance with the present invention; 
     FIG. 4 is a representative schematic block diagram of a control system in accordance with one particular aspect of the present invention; 
     FIG. 5 a  illustrates a cross-sectional view of a nozzle in accordance with one particular aspect of the present invention; 
     FIG. 5 b  illustrates a cross-sectional view of an alternate nozzle in accordance with one particular aspect of the present invention; and 
     FIG. 6 is a flow diagram illustrating one specific methodology for carrying out the control system of FIG. 4 in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention refers to a model for improving the development process of a patterned photoresist material layer disposed on a semiconductor wafer. The model takes into consideration known characteristics of photoacid generators in the photoresist material layer (e.g., concentration, composition, volume ratio, etc.) and known characteristics of a developer used in conjunction with the development of the photoresist material (e.g., concentration, volume, chemical reaction ratio, etc.) to optimize the development of a patterned image onto the photoresist material. The model accomplishes this end by evaluating the water formed across the patterned image as a result of the acid-base reaction during the development process and adjusts at least one of the developer volume, developer concentration and development time to optimize the development process. 
     The present invention will now be described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. The present invention will be described with reference to a method of measuring water present in a development process of a photoresist material and adjustment of the volume, concentration and development time of a developer used in the process. In addition, the present invention will be described with reference to a system and method for monitoring and controlling the developer volume, developer concentration and development time of a developer applied onto a photoresist material layer in order to form a uniformly developed patterned photoresist. It is be understood that the description of these embodiments are merely illustrative and that they should not be taken in a limiting sense. 
     FIG. 1 a  is a flow diagram illustrating one particular methodology for carrying out the present invention. In step  2 , a test wafer is placed on a spin chuck and a photoresist material layer is spin rotated onto the wafer. In step  4 , a pattern is irradiated onto the resist. In step  6 , a developer of a certain concentration and volume is applied onto the wafer and the photoresist material is developed after a development time in step  8 . The developer can be spin coated onto the photoresist material layer. In step  10 , the amount of water formed over the resist caused by the acid-base properties of the photoresist and developer is determined using conventional techniques, such as laboratory measurement equipment or the like, while the test wafer rests on the chuck or after the test wafer is removed from the chuck. The developer and the irradiated or unirradiated resist portions can then be rinsed off the photoresist material layer using a washing solution or the like. In step  12 , the amount of acid consumption is determined based on the amount of water measured in the development process and it is determined if the proper amount of acid consumption has occurred. If the proper amount of acid consumption has occurred (Yes), the values of the developer concentration, the developer volume and the development time are set for production in step  14 . If the proper amount of acid consumption has not occurred (No), one or all of the developer concentration, the developer volume and the development time are adjusted and the method returns to step  2  for repeating the above steps for another wafer. 
     FIGS. 1 b  and  1   c  illustrate a development application system  20 . The development application system  20  includes a developer supply system  23 , a plurality of nozzle assemblies  25  and a parallel developer plate  21 . The parallel developer plate  21  includes a plurality of apertures  27  extending therethrough for applying a developer to a photoresist material  22  that has been spin coated onto a wafer  24 . The wafer  24  is vacuum held onto a rotating chuck  26 . The wafer  24  is spin rotated by a shaft  28  driven by a motor (not shown), so that a photoresist material can be applied to the wafer  24  to form a uniform film or layer of photoresist material  22  over the wafer  24 . After the photoresist material is dried, suitable photolithographic techniques (e.g. irradiation, development) may be performed to form a patterned photoresist material layer. 
     The developer plate  21  forms a parallel plate pair with the wafer  24  during application of the developer. The developer supply system  23  is provided with a supply of concentrated developer (not shown) and a supply of water (not shown) for allowing variation of the concentration of the developer. The nozzles provide the developer plate  21  with a volume of developer for application to the patterned photoresist material layer  22 . The developer plate  21  is disposed in very close proximity with respect to the wafer  24 , such that the developer is squeezed between the two plates (i.e., the developer plate  21  and the wafer  24 ) thereby spreading evenly the developer over the wafer. Since the developer film is stagnant, the transport of acid into base can be monitored and therefore, the development process can be monitored. Furthermore, the proximity of the developer plate  21  to the wafer  24  during application and the size of the plurality of apertures provides for improved localization with respect to development of the photoresist material layer  22 . 
     Referring to FIG. 2 a , a system  30  for monitoring the amount of acid consumption in a development process of a patterned photoresist layer is illustrated A nozzle (not shown) applies a photoresist material to the center of a wafer  24 ′ that is vacuum held onto a rotating chuck  26 ′. The wafer  24 ′ is spin rotated by a shaft  28 ′ driven by a motor (not shown), so that the photoresist material forms a uniform film or layer over the wafer  24 ′. After the photoresist material is dried, suitable photolithographic techniques (e.g. irradiation, development) may be performed to form a patterned photoresist material layer  22 ′ in a desired manner. The system  30  further includes a water particle measurement system  42 . A plurality of lasers  54  are connected to a laser source  44  by fiber optic lines  52 . The laser source  44  is coupled to a laser driver  38  also by fiber optic lines  52 . The laser driver  44  is turned on and off for water particle count measurements by a processor  40 . The patterned photoresist material layer  22 ′ includes a plurality of vias  35  containing water particles  45  therein as a result of the acid-base characteristics of the photoresist material and the developer after a development process is performed. 
     The plurality of lasers  54  send rays of light  56  onto the patterned photoresist material layer  22 ′. The rays of light  56  are reflected to a plurality of detectors  58  which are coupled to the measurement system  42  for measuring the water particle count on the patterned photoresist material layer  22 ′. The light  56  will have different reflecting characteristics if interrupted by water particles  45  as opposed to the patterned photoresist material layer  22 ′ and the vias  45 , thus varying the intensity of the light  56  received by the detectors  58 . Each laser  54  has a corresponding detector  58  for measuring water particle counts. Each laser and detector pair are positioned to detect water particles at different areas within the patterned photoresist material layer. The detectors  58  are connected to the measurement system  42  by fiber optic lines  57  and provide the processor  40  with water particle count information. The processor  40  analyzes the water particle count information, after it is converted into digital form by the measurement system  42 . The processor  40  then outputs the water particle count to a display  36  in a format understandable to a user. 
     It is to be appreciated that lasers  54  and the detectors  58  may be rotatable with respect to the photoresist material layer  22 ′, so that water particle count measurements can be performed at various points within an area of the photoresist material layer  22 ′. It is further appreciated that four lasers  54  and four detectors  58  are shown, but any number of lasers and detectors can be employed to perform the present invention. It also is to be noted that a nozzle for applying the photoresist material is not shown, but the optimal location of the lasers  54  and detectors  58  can be very close to the surface of wafer  24 ′, so that lasers  54  and the detectors  58  do not interfere with the nozzle. 
     The processor  40  receives the measured data from the measuring system  42  and determines the overall water particle count on the patterned photoresist material layer  22 ′ by classical signal analysis and estimation algorithms. The processor  40  is programmed to control and operate the various components within the system  30  in order to carry out the various functions described herein. The processor or CPU  40  may be any of a plurality of processors, such as the AMD K7 and other similar and compatible processors. The manner in which the processor  40  can be programmed to carry out the functions relating to the present invention will be readily apparent to those having ordinary skill in the art based on the description provided herein. 
     A memory  34  which is operatively coupled to the processor  40  is also included in the system  30  and serves to store program code executed by the processor  40  for carrying out operating functions of the system  30  as described herein. The memory  34  includes read only memory (ROM) and random access memory (RAM). The ROM contains among other code the Basic Input-Output System (BIOS) which controls the basic hardware operations of the system  30 . The RAM is the main memory into which the operating system and application programs are loaded. The memory  34  also serves as a storage medium for temporarily storing information such as water particle count measurements, water particle count coordinate tables, laser setting information, detector sensitivity information and other data which may be employed in carrying out the present invention. For mass data storage, the memory  34  may include a hard disk drive (e.g., 10 Gigabyte hard drive). 
     Power supply  32  provides operating power to the system  30 . Any suitable power supply (e.g., battery, line power) may be employed to carry out the present invention. It is to be appreciated that any suitable laser scattering or laser doppler anemometry system may be employed to carry out the present invention and such systems are intended to fall within the scope of the hereto appended claims. Laser scattering and laser doppler anemometry systems are well known in the art, and therefore further discussion related thereto is omitted for sake of brevity. 
     Alternatively, the measurement system  42  can employ polychromatic interferometer system or a monochromatic interferometer system to measure the water particle count. For example, FIG. 2 b  illustrates a monitoring system  30 ′ for monitoring water particles formed from a development process similar to the monitoring system  30  illustrated in FIG. 2 a  were like parts are denoted by like reference numerals. However, the monitoring system  30 ′ includes a light source  68  connected by a fiber optic line  67  to a light driver  66 . The light driver  66  is turned on and off for water particle measurements on the patterned photoresist material layer  22 ′ by the processor  40 . The light source  68  sends a ray of light  63  at the resist layer  22 ′, which is reflected as a ray of light  65  to a light receiver  70  coupled to the measurement system  42  for making water particle measurements. The light receiver  70  is connected to the measurement system  42  by a fiber optic line  69 . In another aspect of the invention, the light source  68  and the light receiver  70  are rotatable so that water particle measurements can be performed at various points along the patterned photoresist material layer  22 ′. In yet another aspect of the invention, the light source  68  comprises a plurality of fiber optic connections and light sources and light receiver  70  includes a plurality of fiber optic connections, and light receivers for detecting water particles  45  along different vias  35  in the resist layer  22 ′. 
     Any suitable interferometry system and/or spectrometry system may be employed to carry out the present invention and such systems are intended to fall within the scope of the hereto appended claims. In one embodiment, the measurement system  42  is a polychromatic interferometer system or a monochromatic interferometer system to measure the water particles formed on the patterned photoresist material layer  22 ′. In another embodiment, the measurement system  42  is a spectrometry system. Interferometry systems and spectrometry systems are well known in the art, and therefore further discussion related thereto is omitted for sake of brevity. It is to be appreciated that the processor  40 , power supply  32 , memory  34  and display  36  may operate similarly in both the monitoring system  30 ′ of FIG. 2 b  and the monitoring system  30  of FIG. 2 a.    
     FIG. 3 illustrates one particular methodology for carrying out the monitoring system  30  of the present invention utilizing a multiple laser and detector arrangement as described in FIG. 2 a . However, a light scattering and detector arrangement as described in FIG. 2 b  can be employed to carry out a similar methodology. In step  120 , power is provided to the system  30  and the processor  40  performs general initializations to the water particle count monitoring system  30 . In step  130 , the processor  40  turns the laser driver  38  on causing lasers  54  to send beams of light  56  across the patterned photoresist material layer  22  to detectors  58 . In step  140 , the measurement system  42  performs a water particle count measurement and sends the data to the processor  40 . In step  150 , the processor  40  analyzed the measured data and outputs the data to the display  36 . The processor  40  then determines if a predetermined period of time has passed in step  160 . If no, the processor repeats step  160 . If yes, the processor  40  advances to step  170  where a new water particle measurement is performed. In step  180 , the processor  40  outputs the updated measurement to the display  36  and returns to step  160 . The present methodology illustrates where the system  30  performs continuous monitoring and updates to the display, and can be disabled by powering down the monitoring system. It is be noted that the processor  40  can be programmed to perform monitoring at specific periods during the development process. 
     FIG. 4 illustrates a closed loop system  60  for controlling the developer concentration, the volume of developer applied and the development time when applying developer to the photoresist material layer  22 ′ on the wafer  24 ′ as shown. The system  60  includes a water particle measurement system  72 . The system  60  includes a light source  73  connected by a fiber optic line  71  to a light driver  61 . The light driver  61  is turned on and off for water particle measurements on the photoresist material layer  22 ′ by the processor  64 , after the development of a pattern onto the photoresist material layer  22 ′. The light source  73  sends light at the resist layer  22 ′, which is reflected to a light receiver  79  coupled to the measurement system  72  for making water particle measurements. The light receiver  79  is connected to the measurement system  72  by a fiber optic line  77 . 
     The processor  64  receives measured water particle data from the measuring system  72  and determines the overall acid consumption of the development process. A memory  62  which is operatively coupled to the processor  64  is also included in the system  60  and serves to store program code executed by the processor  64  for carrying out operating functions of the system  60 . Power supply  75  provides operating power to the system  60 . Any suitable power supply (e.g., battery, line power) may be employed to carry out the present invention. 
     The processor  64  is also coupled to a volume and concentration control system  74 . The volume and concentration control system  74  is operatively coupled to a nozzle  90 , which applies developer to the center of photoresist material  22 ′. It is to be appreciated although a single nozzle  90  is illustrated, the developer application system  20  can be employed that implements a plurality of similar nozzles. 
     The developer material is formed by a combination of concentrated developer and water added to the concentrated developer. The water combines with the concentrated developer to control the concentration of the developer, so that an optimized concentration level can be obtained. The total volume of the developer and the ratio of developer and water mixture is maintained by electronically controlled valves controlled by control line  76  and  78  of the volume and mixture control system  74 . The volume and concentration control system  74  may also be programmed to control a developer contact time. 
     Referring now to FIG. 5 a , the nozzle  90  includes a holder  92  holding a concentrated developer supply tube  98  with one end disposed within the holder  92  and its other end connected to a supply of developer (not shown). A water supply tube  100  has one end disposed within the holder  92 , and its other end connected to a supply of water (not shown). A concentrated developer adjustment valve  102  and a water adjustment valve  104  determine the amount of concentrated developer and water that is received into a mixing chamber  106 . It is to be appreciated that a static mixer may be employed to facilitate mixing. Both valves are electronically controlled by control lines  76  and  78 , respectively, coupled to the volume and concentration control system  74 . The valves can determine the amount of concentrated developer and water that will be applied to the photoresist layer  22 ′, after a pattern is irradiated onto the photoresist layer  22 ′, and also the ratio of the concentrated developer and water in the concentrated developer and water mixture. The mixing of the concentrated developer and water is provided in the mixing chamber  106  simply by simultaneously supplying concentrated developer and water in the chamber. Other mixing techniques can be employed to provide mixing of the concentrated developer and water (e.g. vibration, rotation, churning etc.). A collar  110  is connected to the bottom of the holder  92  and includes a central aperture for allowing a concentrated developer and water mixture supply barrel  108  to pass therethrough. The collar  110  threadingly engages a nozzle tip  112 . Supply barrel  108  is connected to the mixing chamber  106  on one end and passes through the center of nozzle tip  112  on its other end. The supply barrel  108  includes a liquid discharge opening  116  that discharges the concentrated developer and water mixture through a liquid discharge channel  114  of the nozzle tip  112  to the center of the photoresist material layer  22 ′. 
     It is to be appreciated that the mixing of the concentrated developer and water can take place outside the nozzle  90 . Such an example is illustrated in FIG. 5 b , where the supply barrel  108  is disposed inside the nozzle  90  and is coupled to a developer supply line  109  by a coupler  107 . The supply line  109  connects to the mixing chamber  106 . The mixing chamber  106 , the concentrated developer supply tube  98  and the water supply tube  100  are located outside the nozzle  90 . Additionally, the concentrated developer adjustment valve  102  and the water adjustment valve  104  are also located outside the nozzle  90 . 
     FIG. 6 is a flow diagram illustrating one particular methodology for carrying out the present invention with respect to the control system  60  of FIG.  4 . In step  200 , a wafer  24 ′ is loaded onto the rotating chuck  26 ′ and a photoresist layer is spin coated onto the wafer  24 ′. In step  210 , an image or pattern is irradiated onto the photoresist layer after the photoresist layer dries. In step  220 , a predetermined ratio and volume of a concentrated developer and water mixture is applied to the photoresist layer, based on known characteristics of the photoresist material and the developer. The developer is then left on the wafer for a period of time until the photoresist layer is developed. The measurement system  72  then measures the amount of water particles on the patterned photoresist layer  22 ′ at various locations along the wafer in step  230 . In step  240 , the processor  64  determines if the amount of water particles across the patterned photoresist layer  22 ′ equates to the optimal acid consumption of the photoacid generator in the photoresist material based on the particular pattern, the particular desired chemical reaction ratio, the known concentration and amount of acid verse the applied concentration volume and concentration of the developer and the amount of development time. The processor  64  then determines if the proper uniform concentration developer concentration was applied. If the proper uniform concentration of developer was not applied (No), the processor  64  adjust the developer concentration in step  245  and advances to step  250 . If the proper uniform concentration of developer was applied (Yes), the processor  64  simply advances to step  250 . In step  250 , the processor  64  then determines if the proper overall volume of developer was applied. If the proper overall volume of developer was not applied (No), the processor  64  adjust the volume of developer in step  255  and advances to step  260 . If the proper overall volume of developer was applied (Yes), the processor  64  advances to step  260 . In step  260 , the processor  64  then determines if the proper development time was utilized. If the proper development time was not utilized (No), the processor  64  adjust the development time in step  265  and advances to step  270 . If the proper development time was utilized (Yes), the processor  64  advances to step  270 . In step  270 , the processor  64  determines if any adjustments have been made. If any adjustment have been made (Yes), the processor returns to step  200  and repeats the procedure for another wafer, until the optimal developer concentration and volume and optimal development time has been achieved for that particular pattern. If adjustments have not been made (No), the processor  64  stores the variables into memory  62  in step  280  for use in mass production and exits the routine. 
     What has been described above are preferred embodiments of the present invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.