KR100835273B1 - Method of using a target having end of service life detection capability - Google Patents

Abstract

The present invention relates to a method and system for detecting the life of a consumable material slab used by a process tool. In the method and system, the consumable material slab is provided with at least one indicator. Is the value generated by the detector associated with the at least one indicator during operation of the process tool being equal to the warning setting value, between the warning setting value and the alarm setting value, being equal to or greater than the alarm setting value? Determination is made whether or not. A first alert is provided if the value of the signal is equal to or between the alert setpoint and between the alert setpoint and the alert setpoint, wherein the first alert is a predetermined value where the consumable material slab is less than the original amount of the consumable material slab. To approach the amount of. A second alert is provided if the value of the signal is between the alert setpoint and the alert setpoint, and the second alert indicates that the consumable material slab reaches the predetermined amount. An alert is provided if the value of the signal is equal to or above the alert setting, the alert indicating that the consumable material slab has approached or has been reduced to the predetermined amount.

Process tool, consumable material, indicator, warning setpoint, alarm setpoint, first warning

Description

Method of using a target having end of service life detection capability}

1A is a cross-sectional view illustrating an exemplary embodiment of a target with a limitation of service life detection capability.

1B is a top view of an exemplary embodiment of a target having a plurality of limitations of service life indicators.

2 is a block diagram illustrating an exemplary embodiment of a wafer processing system using a target having one or more limitations of service life indicators.

3 is a schematic diagram of an exemplary embodiment of a process chamber in which a target with a limitation of service life detection capability may be used.

4A and 4B are flowcharts illustrating steps of an exemplary method for controlling a gas detector and a process tool in an automatic system communication framework.

5 is a graph illustrating one embodiment of gas detector signal values versus time.

<Description of the symbols for the main parts of the drawings>

10: target 11: slab

12: indicator 112: response surface

114: base surface 116: side wall surface

22a, 22b: opposite open ends 22: tube or enclosure

Related Applications

This application claims U.S. Provisional Application No. 60 / 736,389, filed November 14, 2005, the entire disclosure of which is incorporated herein by reference, US Provisional Application No. 60 / 720,390, filed September 26, 2005. US Provisional Application No. 60 / 728,724, filed Oct. 20, 2005, filed Jun. 29, 2006, the entire disclosure of which is incorporated herein by reference. / 427,602, which is part of US Patent Application No. 11 / 427,618, filed June 29, 2006.

Field of invention

The present invention relates to material deposition. More specifically, the present invention relates to methods of using a target limit of service life detection capability.

Background of the Invention

Physical vapor deposition (PVD) is a well known process for depositing thin film materials on a substrate and is commonly used in the manufacture of semiconductor devices. The PVD process is performed at high vacuum in a chamber comprising a substrate (eg a wafer) and a slab or solid source, such as a PVD target, of the material to be deposited on the substrate. In a PVD process, the PVD target is physically changed from solid to vapor. The vapor of the target material is transferred from the PVD target to the substrate, where it aggregates on the substrate as a thin film.

There are many ways to achieve PVD, including evaporation, e-beam evaporation, plasma spray depositon, and sputtering. Currently, sputtering is the most frequently used method for achieving PVD. During sputtering, a gas plasma is generated in the chamber and sent to the PVD target. The plasma removes or corrodes (stutters) atoms or molecules from the reaction surface of the PVD target with the vapor of the target material as a result of the collision with the high energy particles (ions) of the plasma. Vapor of sputtered atoms or molecules of the target material is transferred to the substrate through the reduced pressure region and aggregates over the substrate to form a thin film of the target material.

PVD targets have finite service lifetimes. Overuse of PVD targets, such as the use after a PVD target service life, raises reliability and safety concerns. For example, PVD target overuse can lead to perforation and system arcing of the PVD target. This can also lead to significant manufacturing losses, PVD system or tool damage and safety issues.

The service life of a PVD target is determined by tracking the number of kilowatt-hours (kw-hrs) currently consumed by accumulated energy, such as a PVD system or a processing tool. However, the accumulated energy method takes time to master and its precision depends only on the hands-on experience of the technician. Even when mastered, the service lives of PVD targets are still smaller than they can have, since approximately 20 to 40 percent of the PVD targets (depending on the PVD target type) are wasted.

Low target usage due to shortened service lifetimes of PVD targets results in high PVD target consumption costs. In practice, PVD target consumption costs are one of the most important costs in semiconductor manufacturing. Thus, if many waste target materials are available, PVD target consumption costs may be substantially reduced. This can also significantly lower semiconductor manufacturing costs and increase profitability.

Low target usage also leads to more frequent replacement of PVD targets, and therefore more frequent maintenance of PVD systems or tools. Moreover, if a PVD target is replaced, time is required to readjust the PVD processing for the new target.

Thus, a need exists for a method that uses a target limit of service life detection capability.

summary

Systems and methods for detecting the lifetime of consumable material slabs used by process tools are described. In the method and system, the consumable material slab is provided with at least one detector or indicator. At this time, is the value generated by the detector associated with the at least one indicator during operation of the process tool equal to the warning setting value, between the warning setting value and the alarm setting value, the same as the alarm setting value or the alarm setting? A determination is made whether or not it is above the setting. A first alert is provided if the value of the signal is equal to or between the alert setpoint and between the alert setpoint and the alert setpoint, wherein the first alert is a predetermined value where the consumable material slab is less than the original amount of the consumable material slab. To approach the amount of. A second alert is provided if the value of the signal is between the alert setpoint and the alert setpoint, and the second alert indicates that the consumable material slab reaches the predetermined amount. An alert is provided if the value of the signal is equal to or greater than the alert setting, the alert indicating that the consumable material slab has approached or has been reduced to the predetermined amount.

Detailed description of the invention

Disclosed herein are systems and methods for detecting a limit of service life of a target or other consumable material. The target may be in the form used as a source material in a material deposition process, such as physical vapor deposition (PVD). 1A is a cross-sectional view illustrating an exemplary embodiment of a target with a limit of service life detection capability, indicated by the number 10. The target 10 is a consumable material slab (target slab) 11 and one or more service life limits that may indicate that the target slab 11 is approaching a predetermined amount and / or reduced to a predetermined amount. Detectors or indicators 12.

The target slab 11 has a reaction surface 112, a base surface 114 facing the reaction surface 112, and a sidewall surface 11.6 extending between the reaction surface 112 and the base surface 114. It includes. The target slab 11 can be formed into any suitable and suitable shape, including, for example, circular, square, rectangular, oval, triangular, irregular shape, and the like. The target slab 11 may, in one embodiment, have a diameter of 12 inches (in the case of a circular slab) and a thickness of 0.250 inches. In other embodiments, the target slab 11 may be formed in any other suitable and suitable dimensions. The target slab 11 may be any suitable and suitable source, including, for example, nickel, nickel platinum alloys, nickel titanium alloys, cobalt, aluminum, copper, titanium, tantalum, tungsten, ITO, ZnS-SiO ₂ . It can be made of a material.

In one exemplary embodiment, the one or more indicators 12 may each include a gas indicator partially or wholly embedded in the base surface 114 of the target slab 11. However, the one or more indicators 12 may also indicate other types of indicators (eg, filaments, electrodes, and the like) that may indicate that the target slab 11 is approaching a predetermined amount and / or reduced to a predetermined amount. And / or second material indicators). If more than one indicator 12 is used, the indicators 12 are arranged approximately equally across the target slab 11 to increase the detection resolution, as shown in the plan view of FIG. 1B.

1A and 1B, each gas indicator 12 may, in one exemplary embodiment, comprise a tube or enclosure 22 having opposing open ends 22a, 22b. have. In one exemplary embodiment, the tube 22 may be made of the same material as the target slab 11. The open ends 22a, 22b of the tube 22 are closed and hermetically sealed by closures (not shown). The tube 22 is filled with an inert gas 24 such as helium, krypton or the like that does not affect the material deposition treatment result. In other embodiments, the tube 22 may also be filled with or include a liquid or solid that can be detected when released from the tube 22. Other embodiments of targets and indicators and methods of making such targets and indicators are described in US patent application Ser. No. 11 / 427,602, filed June 29, 2006, US, filed June 29, 2006. It is described in detail in patent application no. 11 / 427,618, the entire disclosures of which are incorporated herein by reference.

The diameter of the tube 12 should be small enough so that it is not exposed until almost all target slabs 11 are consumed. In one exemplary embodiment, the tube 22 may have a diameter of about 0.5 mm.

The target slab 11 is corroded or consumed during processing in the process chamber, for example by process forces such as sputtering plasma. As long as the tube (s) 22 of the indicator (s) 12 remain unbroken, the inert gas 24 will remain undisturbed there. If the corrosion and consumption of the target slab 11 is exposed to the tube (s) 22 of the indicator (s) 12 embedded in the target slab 11 and then broken by process forces, the indicator (s) The tube (s) 22 of) 12 will begin to release or leak inert gas 24 contained therein into the process chamber, whereby the target 10 will soon approach its service life end point. Provide a detectable signal indicative of that. Such indication may be used to adjust and / or limit the number of lots of wafers, etc. to be further processed for that particular target 10.

Continued treatment of the target 10 may in turn result in further release or leakage of inert gas into the process chamber (eg from the tubes 22 of the other indicators 12) and / or accelerated release of the inert gas or Corrodes or consumes the target slab 11 and the tube (s) 22 to the point where leakage (eg from further corrosion of the tube (s) 22) will occur, thereby service life of the target 10 It will provide a detectable signal indicating that the endpoint has been reached. This indication can be used to further adjust and / or further limit the number of wafers to be further processed, etc. for a particular target, or to halt the process chamber or replace the target with another (new) target.

In one embodiment, the end of service life (EOL) detection capability provided by one or more indicators 12 is such that the target slab 11 has a residual amount less than 0.5 percent of the original amount of slab material. To be reduced. It also optimizes target usage, reduces target costs, increases the length of preventive maintenance cycles, shortens process adjustment time, and increases utilization of related manufacturing tools and process chambers.

Target 10 may be used in material deposition processes such as PVD without significant hardware changes and / or changes. Moreover, the target 10 may be in other forms, including, for example, magnetron systems, capacitively coupled plasma (CCP) systems, and inductively coupled plasma (ICP) systems. Can be used in magnetic systems. The target 10 may also be used in all types of power systems, including without limitation direct current power systems, alternating current power systems, and radio frequency power systems.

2 is a block diagram illustrating an exemplary embodiment of a wafer processing system 100 using a target with one or more indicators. The system 100 includes a manufacturing automation system 110 having a computer, such as a process tool 120, such as a wafer process chamber, and a computer controlled monitoring device 130.

As shown in FIG. 3, the process chamber 120 includes a wafer stage 122 disposed inside the interior 121 to support the interior 121 and the wafer 124 to be processed. The target 10 of the present invention may be mounted on the wafer stage 122 in the interior 121 of the process chamber 120. The gas detection / monitoring device (gas detector) 130 is mounted outside the process chamber 120 in a manner that allows it to detect and / or monitor the release of inert gas 24 into the interior 121 of the chamber 120. Can be. The gas detector 130 may include, for example, an optical emission spectrometer (OES), or a residual gas analyzer (RGA). Alternatively, gas detector 130 may include a pressure monitoring device (GP) that measures the pressure of the inert gas 24 in the tube of the indicator 12. During processing, gas detector 130 generates a range of detector values in response to the amount of inert gas to be emitted by one or more indicators 12 of target 10.

As shown in FIG. 2, an automatic system communication framework or network provides two-way communication between manufacturing automation system 110 and gas detector 130, manufacturing automation system 110. Two-way communication between the process chamber 120 and two-way communication between the gas detector 130 and the process chamber 120, thereby being used in the wafer processing system 100. The automation system communication framework allows the gas detector 130, which detects and monitors gas emissions from one or more indicators 12 of the target 10, to automatically determine the number of semiconductor wafer lots or lots of items or materials to be processed. Which is processed in the process chamber 120 with a given target 10, thereby optimizing target utilization, reducing target costs, increasing the length of preventive maintenance cycles, and The adjustment time is shortened and the utilization rate of the process chamber 120 is increased. For example, "one wafer lot" can be defined as any number of wafers to be processed in a single carrier or cassette, where the wafers in one wafer lot The maximum number can be 25 wafers.

4A and 4B are flowcharts illustrating steps of an exemplary method for controlling gas detector 130 and chamber / tool 120 in an automated system communication framework. The control method is performed by a computer of a manufacturing automation system, and typically can be implemented by, for example, a software program. The method begins at step 200 by activating the gas detector 130 in an automation system communication framework. In step 205 certain parameters of the gas detector 130 are initially set. In one exemplary embodiment, the initial settings of the gas detector parameters may include the following:

The connection flag is set to 1 (where 1 = enable, 0 = disable);

The number of warnings set to 0, where the number can be 0, 1, 2;

A count number set to four (or a number greater than three wafer lots);

An alarm flag set to 0 (where 1 = enable, 0 = disable);

Initial gas detector / inert gas background setting B, which may be entered or may be a default setting;

Gas detector / inert gas warning setting W, which may be entered or may be a default setting;

Gas detector / inert gas alarm setting A, which may be entered or may be a default setting;

A message sent to the chamber / tool for a first warning, such as 1S, called "first target warning";

A message sent to the chamber / tool for a second warning, such as 2S, called "second target warning";

A message sent to the chamber / tool for an alarm, such as A, called a "target alarm."

In response to a suitable signal from the gas detector (when the gas detector detects specific amounts of inert gas emitted from the tube of the indicator), the computer of the manufacturing automation system 110 sends a corresponding one of the above messages to the process chamber / Transfer to the tool and pause the process chamber / tool for further processing.

5 is a graph showing one embodiment of gas detector signal values versus time corresponding to the amounts of inert gas detected. It should be understood that other embodiments of gas detector signal values versus time may be envisioned. As shown, the gas detector signal value for an inert gas background setting may be a value B, the gas detector signal value for the inert warning setting may be a value W, and the gas detector for an inert gas alarm setting The signal value may be a value A. At the start of the process (indicated by period B), there is no release of an inert gas from the indicator tube, for example krypton, and therefore the detected signal value is below the background signal value, for example 10 ⁻¹¹ amperes. After a treatment period such as 2600 Kw-hr, the target is consumed and the inert gas is released from the tube of the indicator. If the release of the inert gas exceeds the warning setting, for example, if the gas detector signal value is ^10-8 amps, the gas detector sends a first warning signal, such as 1S, to the chamber / tool. If the release of inert gas exceeds the warning setting for a second time, the gas detector sends a second warning signal, such as 2S, to the chamber / tool. If the release of an inert gas exceeds the alarm setting, for example if the gas detector signal value is 10 ⁻⁷ amperes, the gas detector sends an alarm signal such as A to the chamber / tool.

In one embodiment, when the first warning signal 1S is transmitted, chamber / tool processing is paused after processing of the current wafer lot and a counter associated with the computer of the manufacturing automation system 110 is triggered to be greater than three. The initial parameter setting (using the above example of initial parameter settings) is set to the default setting of three wafer lots. The first alert indicates that three wafer lots can continue to be processed with the current (residual) target. When the second warning signal 2S is sent, the chamber / tool processing will be paused (after the current wafer lot has been processed), and the second warning will continue to be processed with the two residual wafer current targets. It shows what can be. When the alert signal A is sent, chamber / tool processing is paused (after the current wafer lot has been processed) and the alert indicates that one wafer lot can continue to be processed with the current residual target. .

Referring again to FIGS. 4A and 4B, at step 210 of the method, it is determined whether the connection and alert flag settings are correct. If the connection and alert flag settings are incorrect, then the connection and alert flags are checked in step 265 and set again in step 205. If the connection and alert flags settings are correct, then the gas detector value is read in step 215.

In general, the gas detector value may be less than or equal to the background setting B if the tube (s) 22 of the target indicator 12 remain undamaged by process forces. Corrosion and consumption of the target slab 11 causes the tube (s) 22 of the indicator (s) 12 to be exposed and subsequently broken by process forces, The tube (s) 22 will begin to discharge the inert gas 24 contained therein into the process chamber 120. Gas detector 130 will detect inert gas emissions to the process chamber 120 and generate detector values approximately above the background setting B. Finally, the gas detector values will extend and even exceed the alarm setting A, depending on the amount of inert gas released into the process chamber 120.

In step 220, a determination is made whether the gas detector value read in step 215 is between an inert gas warning setting value W and an inert gas alarm setting value A. If the gas detector value is between the inert gas warning setting value W and the inert gas warning setting value A, then a determination is made at step 275 as to whether the warning number is equal to zero.

If the number of warnings in step 275 is equal to zero, then processing in the process chamber 120 may be paused in step 280 such that a "first target warning" message may be sent to the process chamber 120 and the number of warnings is set to one. Can be. The message " first target warning " in step 280 triggers the counter so that an initial parameter setting greater than 3 is set to the default setting of three wafer lots, which default setting will continue to be processed with the current residual target 10. Number N1 of residual wafer lots, such as, for example, three wafer lots. At step 285, a determination is then made as to whether the process chamber 120 has been checked and then restarted by an engineer or technician. This step ensures that the engineer / technician notices the status of the warning (ie, an indication associated with the warning about the number of residual wafer lots that can be processed) and checks this status personally. Thereafter, the engineer / technician releases the process chamber from a pause state and restarts the process chamber for processing. When the process chamber is restarted, the method then returns to the gas detector value reading step 215. If the process chamber 120 is not restarted, then the method returns to process chamber restart determination step 285 where a determination is made as to whether the process chamber 120 has been checked and restarted by an engineer or technician. Thereafter the counter of the residual number N1 of wafer lots for processing after step 285 is decremented by one after completion of the current wafer lot.

Returning to step 275 again, if the number of warnings is equal to zero, then processing in process chamber 120 may be paused in step 290 so that a “second target warning” message may be sent to process chamber 120. The number of warnings is not equal to zero, and the number may be one. The "second target warning " message indicates the number of wafer lots, such as, for example, two wafer lots, to continue processing with the current residual target 10. The number of residual wafer lots for processing in step 290 is compared with the counter number N1 of residual wafer lots for processing after step 285. A number less than two is updated to counter and this number of remaining wafer lots will be processed in step 290. At step 235, a determination is then made as to whether the process chamber 120 has been checked by an engineer or technician and restarted.

Returning to step 220, if the gas detector value read in step 215 is not between an inert gas warning setting value W and an inert gas alarm setting value A, then the gas detector value read in step 215 is an inert gas alarm setting value. It is determined in step 225 whether it is above A. If the gas detector value at step 215 is not greater than or equal to the inert gas alarm setting value A, then steps 215, 220 and the like are performed again. However, if the gas detector value read in step 215 is greater than or equal to the inert gas alarm setting A, then the process in process chamber 120 is paused in step 230 so that a " warning " Can be. The "warning" message indicates the number of residual wafer lots to be processed with the current target, for example one lot. The number of residual wafer lots for processing in step 230 is compared with the counter number N1 of residual wafer lots for processing after step 285 (or this counter is now equal to 4, which has not yet been triggered). A number less than two is updated with the counter and this number of remaining wafer lots will be processed in step 230. At step 235, a determination is then made as to whether the process chamber 120 has been checked by an engineer or technician and restarted.

If the process chamber 120 is restarted in step 235, the detector value is then read in step 240. If the process chamber 120 has not been restarted, the method then returns to process chamber restart determination step 235 where a determination is made as to whether the process chamber 120 has been checked by an engineer or technician and restarted.

In step 240 the gas detector value is read and a determination is made in step 245 whether the gas detector value in step 240 is greater than or equal to the inert gas warning setting value W. If the gas detector value in step 245 is not greater than the inert gas warning setting value W, it is determined in step 246 whether the lot being processed at this time is the final lot for processing in the chamber 120, which is the counter number of the remaining wafers. N1 is equal to 0. If the lot being processed is the final lot at step 246, the method then goes to step 247 to complete the processing of the current lot and to pause the chamber for preventive maintenance. If the lot that is currently moving in step 246 is not the last lot, then the method returns to step 240.

If the gas detector value in step 245 is greater than or equal to the inert gas warning setting W, a message "can run present processing lot only" is sent to process chamber 120 in step 250. This indicates that only the current lot can continue to be processed with the current target. At this moment of step 250, the counter number N1 of the remaining wafer lots is automatically set to zero. After completion of step 250, the method moves to step 247 to complete the current processing lot and suspend the chamber for preventive maintenance. The process chamber 120 is stopped by the manufacturing automation system 110.

While the invention has been described in connection with the above, various modifications and variations can be made without departing from the spirit of the invention. Accordingly, all such modifications and variations are considered to be within the scope of the following claims.

The present invention provides a system and method for detecting the lifetime of consumable material slabs used by process tools.

Claims (15)

A method of detecting the life of a consumable material slab used by a process tool, Providing at least one indicator on the consumable material slab; Is the value of the signal generated by the detector associated with the at least one indicator during operation of the process tool equal to a warning setting value, or between the warning setting value and an alarm setting value, Determining whether it is equal to or greater than an alarm setting value; And Providing a first alert if the value of the signal is equal to or between the alert setpoint and the alert setpoint, wherein the first alert indicates that the consumable material slab is disposed of the consumable material slab. A method for detecting the life of a consumable material slab, indicating approaching a predetermined amount less than the original amount. The method of claim 1, Wherein the operation of the process tool is suspended when the first alert is provided. The method of claim 2, Reducing the number of item lots to be further processed by the process tool using the consumable material slab. The method of claim 1, Providing an alarm if the value of the signal is equal to or greater than the alarm setting value, wherein the alarm is such that the consumable material slab approaches or is reduced to the predetermined amount. Life detection method of a consumable material slab. The method of claim 1, Providing a second alert if the value of the signal is between the alert setpoint and the alert setpoint, wherein the second alert indicates that the consumable material slab reaches the predetermined amount. Life detection method of material slab. The method of claim 1, And the consumable material slab comprises a physical vapor deposition target. The method of claim 1, The at least one indicator is: An enclosure at least partially embedded within the consumable material slab; And And one of a filament element and electrode elements, disposed in the enclosure. The method of claim 1, The at least one indicator is: An enclosure at least partially embedded within the consumable material slab; And And a gas, a liquid, and a solid disposed in the enclosure. The method of claim 8, Wherein one of said gas, liquid, and solid can be detected by said detector when discharged from said enclosure. As a system, Process tools; Consumable material slabs used by the process tool; At least one indicator in the slab associated with the consumable material slab; A detector associated with the at least one indicator; And And a computer in communication with the detector to allow lifetime detection of the consumable material slab. The method of claim 10, The computer determines whether the value of the signal generated by the detector during operation of the process tool is equal to the warning setting value, is between the warning setting value and the alarm setting value. Determine whether equal to or greater than the alarm setting value; A first warning is provided if the value of the signal is equal to or between the warning setting and the warning setting, the first warning being such that the consumable material slab is less than the original amount of the consumable material slab; The system, indicating access to a small predetermined amount. The method of claim 11, The computer is in communication with the process tool and suspends the operation of the process tool when the first alert is provided. The method of claim 11, The at least one indicator is: An enclosure at least partially embedded within the consumable material slab; And And one of the filament element and the electrode elements disposed in the enclosure. The method of claim 11, The at least one indicator is: An enclosure at least partially embedded within the consumable material slab; And And one of a gas, a liquid, and a solid disposed in the enclosure. The method of claim 14, One of the gas, liquid, and solid can be detected by the detector when released from the enclosure.

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