Method of cleaning ion implanter current dose meter shutter

Abstract

The application provides a cleaning method for a current dosimeter baffle of an ion implanter, determines a previous ion source type in an ion implantation process and a to-be-converted ion source type; an electric field is applied, a processing gas is introduced into the ion implanter according to the previous ion source type, so that the first processing gas is ionized to form a first processing ion beam, the width of the first processing ion beam is a first mark size, and a first-stage cleaning treatment is performed on the current dosimeter baffle; according to the to-be-converted ion source type, a second processing gas is introduced into the ion implanter, so that the second processing gas is ionized to form a second processing ion beam, the width of the second processing ion beam is a second mark size greater than the first mark size, and a second-stage cleaning treatment is performed on the current dosimeter baffle. After the aging process pre-cleaning is performed on the current dosimeter baffle, the cleanliness of the current dosimeter baffle is obviously improved, and the overall off-line detection of the ion condition of the ion implanter can be obviously reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method for cleaning the baffle of an ion implanter current dosimeter. Background Technology

[0002] In semiconductor integrated circuit manufacturing processes, especially below the 28-nanometer node, the increase in particles and the presence of unpredictable burst particles will directly affect the overall yield of the product.

[0003] In the ion implantation (IMP) process, before ion implantation of the product, based on past experience, the ion implantation equipment (such as...) Figure 3 As shown, the ion source and beamline sections within the machine exhibit severe ion particle conditions. Therefore, an aging process is initiated first. Traditionally, this involves using the Aging Recipe (an argon-based aging process menu) to pre-clean these two sections of the machine, aiming to reduce ion concentration during subsequent ion implantation. However, this previous aging process did not clean the turning faraday of the ion implanter within the process chamber, which is also a significant source of ions. Figure 3 This resulted in an overall deviation in the online and offline ion detection of the current testing equipment in SEN.

[0004] The overall particle condition of the current ion implanter deviates, and is often accompanied by abnormal points of jump in height. Figure 1 ).

[0005] To address the aforementioned issues, a novel cleaning method for the baffle of the current dosimeter in an ion implanter is required. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a cleaning method for the baffle of the current dosimeter of an ion implanter, which solves the problem that the aging process in the prior art does not clean the baffle of the current dosimeter of the ion implanter inside the process chamber, which is also an important source of ions. This leads to the problem of overall deviation between online and offline ion detection by the current implanter in SEN.

[0007] To achieve the above and other related objectives, the present invention provides a method for cleaning the baffle of an ion implanter current dosimeter, comprising:

[0008] Determine the types of ion sources currently in use and the types of ion sources to be converted during the ion implantation process;

[0009] An electric field is applied, and a processing gas is introduced into the ion implanter according to the type of prior ion source, so that the first processing gas is ionized to form a first processing ion beam, the width of the first processing ion beam being the first mark size;

[0010] The first processing ion beam performs a first-stage cleaning process on the current dosimeter baffle in the process chamber of the ion implanter, which may be a SEN ion implanter.

[0011] According to the type of ion source to be converted, a second processing gas is introduced into the ion implanter, so that the second processing gas is ionized to form a second processing ion beam, the width of the second processing ion beam being a second mark size larger than the first mark size;

[0012] The second processing ion beam irradiates the current dosimeter baffle to perform a second-stage cleaning process on the current dosimeter baffle.

[0013] Preferably, the material of the current dosimeter baffle is graphite.

[0014] Preferably, the type of the preceding ion source includes any one of Ar, As, P, and BF2.

[0015] Preferably, the type of ion source to be converted includes any one of Ar, As, P, and BF2.

[0016] Preferably, the step of introducing a first processing gas into the ion implanter according to the type of ion source in the pre-ion implantation process to perform a first-stage cleaning process on the current dosimeter baffle in the process chamber of the ion implanter includes: introducing Ar, As, P and BF2 into the ion implanter according to the type of ion source in the pre-ion implantation process to perform a first-stage cleaning process on the current dosimeter baffle.

[0017] Preferably, the method for adjusting the width of the first processed ion beam to the first mark size includes: the ion implanter is provided with an electrostatic scanning device composed of X and Y electrodes, and the first processed ion beam passes through the X electrode so that the width of the first processed ion beam in the X direction is offset to the first mark size.

[0018] Preferably, the size of the first mark is less than or equal to 120 mm.

[0019] Preferably, the first stage of cleaning takes 10 to 30 minutes.

[0020] Preferably, the step of introducing a second processing gas into the ion implanter according to the type of ion source in the pre-ion implantation process to perform a second-stage cleaning process on the current dosimeter baffle in the process chamber of the ion implanter includes: introducing Ar, As, P and BF2 into the ion implanter according to the type of ion source in the pre-ion implantation process to perform a second-stage cleaning process on the current dosimeter baffle.

[0021] Preferably, the method for adjusting the width of the second processed ion beam to the second mark size includes: the ion implanter is provided with an electrostatic scanning device composed of X and Y electrodes, and the second processed ion beam passes through the X electrode so that the width of the first processed ion beam in the X direction is offset to the second mark size.

[0022] Preferably, the size of the second mark is 145 to 155 mm.

[0023] Preferably, the second stage of cleaning takes 10 to 30 minutes.

[0024] As described above, the cleaning method for the baffle of the ion implanter current dosimeter of the present invention has the following beneficial effects:

[0025] By performing an aging process to pre-clean the baffle of the current dosimeter, the cleanliness of the baffle is significantly improved, and the overall offline detection ion status of the ion implantation machine is significantly reduced. Attached Figure Description

[0026] Figure 1 This is a schematic diagram showing the offline current monitoring of particle status in a conventional SEN ion implanter.

[0027] Figure 2 This diagram illustrates the current status of various particle types in a SEN ion implanter in the prior art.

[0028] Figure 3 The diagram shows a schematic of an existing ion implantation machine.

[0029] Figure 4 The diagram shown is a schematic diagram of the formation of the first processed ion beam according to an embodiment of the present invention;

[0030] Figure 5 The diagram shown illustrates the formation of the second processed ion beam according to an embodiment of the present invention.

[0031] Figure 6 This is a schematic diagram showing the offline monitoring of particle status after cleaning the current dosimeter according to an embodiment of the present invention.

[0032] Figure 7The diagram shows a cleaning method for the baffle of the ion implanter current dosimeter according to the present invention. Detailed Implementation

[0033] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] Please see Figure 7 The present invention provides a method for cleaning the baffle of an ion implanter current dosimeter, comprising:

[0035] Step 1: Determine the types of ion sources currently in use and the types of ion sources to be converted during the ion implantation process;

[0036] It should be noted that the particle condition of current ion implanters is generally unpredictable, and often accompanied by abnormal spikes in particle size. Figure 1 The inventors, through long-term offline monitoring and analysis, discovered that the number of jumps and the mean value of BF2 were both higher than those of other source species such as AS / P / B. Figure 2 Regarding the phenomenon that BF2 monitoring is worse than other source species such as AS / P / B, the inventors analyzed the log data during ion implantation and found that the ion beam width of BF2 in the X-axis direction is 120mm. We call this parameter the current marker size, while the marker sizes of other monitoring source species are all below 80mm. The BF2 ion beam marker size is relatively large, so the area of ​​the beam bombarding the current dosimeter baffle 101 (Faraday cup) in the process cavity during ion implantation is larger than that of other source species. This makes it easier to cause small-sized ions to be lifted, resulting in a worse ion situation on the graphite plate.

[0037] Further analysis of the product recipes revealed that the ion beam markings in the indium source D050K* and D055K* recipes were also larger than 80mm. This would result in a larger number of ion beams bombarding the current dosimeter baffle 101, generating particles and affecting product yield.

[0038] In embodiments of the present invention, the type of the preceding ion source includes any one of Ar, As, P, and BF2.

[0039] In embodiments of the present invention, the types of ion sources to be converted include any one of Ar, As, P, and BF2.

[0040] Step 2, please refer to 4, apply an electric field, and according to the type of ion source, introduce a processing gas into the ion implanter, so that the first processing gas is ionized to form a first processing ion beam 102. The width of the first processing ion beam 102 is the first mark size L1. The ion implanter can be a SEN ion implanter.

[0041] Step 3: The first processing ion beam 102 performs the first stage cleaning treatment on the current dosimeter baffle 101 in the process chamber of the ion implanter, which is the first cleaning treatment process of the original machine recipe. Here, the process chamber at the ion source end and the ion beam end can be cleaned, but the cleaning effect of the ion implanter current dosimeter baffle 101 (Tuning Faraday) in the process chamber is poor. The current dosimeter baffle 101 is usually located in the process chamber.

[0042] In an embodiment of the present invention, a first processing gas is introduced into the ion implanter according to the type of ion source in the pre-ion implantation process to perform a first-stage cleaning process on the current dosimeter baffle 101 in the process chamber of the ion implanter, including: introducing Ar, As, P and BF2 into the ion implanter according to the type of ion source in the pre-ion implantation process to perform a first-stage cleaning process on the current dosimeter baffle 101.

[0043] In an embodiment of the present invention, the method for adjusting the width of the first processed ion beam 102 to the first mark size L1 includes: an electrostatic scanning device composed of X and Y electrodes is provided in the ion implanter, and the width of the first processed ion beam 102 in the X direction is shifted by the X electrode to the first mark size L1.

[0044] In an embodiment of the present invention, the first mark size L1 is less than or equal to 120 mm.

[0045] In an embodiment of the present invention, the first stage of cleaning takes 10 to 30 minutes.

[0046] Step 4, please refer to Figure 5 According to the type of ion source to be converted, a second processing gas is introduced into the ion implanter, so that the second processing gas is ionized to form a second processing ion beam 103. The width of the second processing ion beam 103 is greater than the second mark size L2 of the first mark size L1.

[0047] Step 5: Irradiate the current dosimeter baffle 101 with the second processing ion beam 103 to perform a second-stage cleaning process on the current dosimeter baffle 101. This involves retaining the original aging process while adding a pre-cleaning aging process, covering the wider area of ​​the current dosimeter baffle 101. This achieves the pre-cleaning effect for all ion implantation recipes.

[0048] In an embodiment of the present invention, a second processing gas is introduced into the ion implanter according to the type of ion source in the preceding ion implantation process to perform a second-stage cleaning process on the current dosimeter baffle 101 in the process chamber of the ion implanter. This includes: introducing Ar, As, P and BF2 into the ion implanter according to the type of ion source in the preceding ion implantation process to perform a second-stage cleaning process on the current dosimeter baffle 101.

[0049] In an embodiment of the present invention, the method for adjusting the width of the second processed ion beam 103 to the second mark size L2 includes: an electrostatic scanning device composed of X and Y electrodes is provided in the ion implanter, and the second processed ion beam 103 passes through the X electrode to offset the width of the first processed ion beam 102 in the X direction to the second mark size L2.

[0050] In an embodiment of the present invention, the second mark size L2 is 145 to 155 mm.

[0051] In an embodiment of the present invention, the second stage cleaning process takes 10 to 30 minutes.

[0052] In the embodiments of the present invention, after cleaning by the method of the present invention, the cleanliness of the Tuning Faraday graphite plate was significantly improved, and the overall offline monitoring of the SEN machine, including the BF2 ion status, was significantly reduced. Figure 6 ).

[0053] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0054] In summary, by performing an aging process to pre-clean the current dosimeter baffle, the cleanliness of the baffle is significantly improved, and the overall offline ion detection status of the ion implantation equipment is significantly reduced. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0055] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method of cleaning an ion implanter current dose meter shutter, comprising: At least comprising: determining a preceding ion source species in an ion implantation process and a to-be-converted ion source species; applying an electric field, according to the preceding ion source species, a first processing gas into an ion implanter, so that the first processing gas is ionized to form a first processing ion beam, a width of the first processing ion beam being a first mark size, wherein the first mark size is less than or equal to 120 mm; so that the first processing ion beam performs a first stage cleaning process on a current dosimeter shutter in a process chamber of the ion implanter; according to the to-be-converted ion source species, a second processing gas into the ion implanter, so that the second processing gas is ionized to form a second processing ion beam, a width of the second processing ion beam being a second mark size greater than the first mark size, wherein the second mark size is 145 to 155 mm; so that the second processing ion beam irradiates the current dosimeter shutter to perform a second stage cleaning process on the current dosimeter shutter.

2. The method of claim 1, wherein: The material of the current dosimeter shutter is graphite.

3. The method of claim 1, wherein: The preceding ion source species includes any one of Ar, As, P, and BF2.

4. The method of claim 3, wherein: The to-be-converted ion source species includes any one of Ar, As, P, and BF2.

5. The method of claim 1, wherein: According to the ion source species in a preceding ion implantation process, a first processing gas is introduced into the ion implanter to perform a first stage cleaning process on a current dosimeter shutter in a process chamber of the ion implanter, including: according to the ion source species in the preceding ion implantation process, Ar, As, P, and BF2 are introduced into the ion implanter to perform the first stage cleaning process on the current dosimeter shutter.

6. The method of claim 5, wherein: The width of the first processing ion beam is adjusted to a first mark size by an electrostatic scanning device composed of X and Y electrodes in the ion implanter, and the first processing ion beam passes through the X electrode to offset the width of the first processing ion beam in the X direction to the first mark size.

7. The method of claim 1, wherein: The time of the first stage cleaning process is 10 to 30 minutes.

8. The method of claim 1, wherein: According to the ion source species in a to-be-converted ion implantation process, a second processing gas is introduced into the ion implanter to perform a second stage cleaning process on a current dosimeter shutter in a process chamber of the ion implanter, including: according to the to-be-converted ion source species, Ar, As, P, and BF2 are introduced into the ion implanter to perform the second stage cleaning process on the current dosimeter shutter.

9. The method of claim 8, wherein: The width of the second processing ion beam is adjusted to a second mark size by an electrostatic scanning device composed of X and Y electrodes in the ion implanter, and the second processing ion beam passes through the X electrode to offset the width of the first processing ion beam in the X direction to the second mark size.

10. The method of claim 1, wherein: The time of the second stage cleaning process is 10 to 30 minutes.

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