Test method and test structure of photoresist layer
By forming test film layer areas of different thicknesses on the test wafer and measuring the resistance before and after injection, the photoresist layer with the minimum thickness is selected as the target thickness. This solves the problems of high photoresist layer thickness testing cost and large impact on CD in the existing technology, and realizes efficient and low-cost photoresist layer thickness selection.
Patent Information
- Application Number
- CN202510772056.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-10
- Publication Date
- 2025-09-09
AI Technical Summary
It is difficult to effectively test and select a photoresist layer of appropriate thickness to block ion implantation with existing technologies, resulting in a significant impact on the critical dimension (CD) of the ion implantation area. In addition, existing testing methods are costly and labor-intensive.
By forming test film areas of different thicknesses on the test wafer and covering them with a photoresist layer, the resistance before and after injection is measured to determine the ion implantation blocking effect. The photoresist layer with the minimum thickness is selected as the target thickness, and the atomic layer deposition process is used to precisely control the film thickness.
The method realizes the testing of multiple photoresist layer thicknesses on the same wafer, reduces the testing cost, reduces the number of test wafers used, and reduces the influence of the photoresist layer on the CD of the ion implantation area.
Smart Images
Figure CN120613282A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the field of semiconductor manufacturing, and specifically to a testing method and testing structure for a photoresist layer. Background Art
[0002] In the current semiconductor process, there are multiple ion implantation related processes. In order to implant ions into part of the wafer, it is necessary to block the area of the wafer that does not require ion implantation with photoresist before the ion implantation. This photoresist that selectively blocks ion implantation is regarded as a temporary protective layer, which can be called a photoresist layer.
[0003] However, a photoresist layer that is too thin cannot completely block ion implantation, while a photoresist layer that is too thick may affect the CD (critical dimension) of the ion implantation area. Therefore, it is necessary to select a photoresist layer with accurate thickness to block ion implantation in order to reduce the impact on the CD of the ion implantation area.
[0004] In this context, how to provide a test solution for the photoresist layer to test the thickness of the photoresist layer selected for blocking ion implantation, and thereby provide support for reducing the impact of the photoresist layer on the CD of the ion implantation area, has become an urgent problem to be solved by those skilled in the art. Summary of the Invention
[0005] In view of this, embodiments of the present application provide a method and structure for testing a photoresist layer, which can test the thickness of a photoresist layer selected for blocking ion implantation, thereby providing support for reducing the impact of the photoresist layer on the CD of the ion implantation area.
[0006] To achieve the above objectives, the embodiments of the present application provide the following technical solutions.
[0007] In a first aspect, an embodiment of the present application provides a method for testing a photoresist layer, comprising:
[0008] Provide test wafers;
[0009] forming a test film layer on the test wafer, wherein the test film layer comprises at least a plurality of test film layer regions with different thicknesses;
[0010] Measure the pre-injection resistance of each test film area;
[0011] forming a photoresist layer on the test film layer, wherein the photoresist layer at least includes a plurality of photoresist layer regions with different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region correspondingly covers one test film layer region;
[0012] Performing ion implantation on the test wafer on which the photoresist layer is formed, and then removing the photoresist layer;
[0013] Measure the post-implantation resistance of each test film area;
[0014] Determine the ion implantation blocking effect of each test film layer region based on the pre-implantation resistance and post-implantation resistance of each test film layer region, wherein the photoresist layer region covered by the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region;
[0015] The minimum thickness among the thicknesses of the target photoresist layer region is determined as the thickness of the photoresist layer used in the actual process.
[0016] Optionally, determining the ion implantation effect of each test film layer region according to the pre-injection resistance and post-injection resistance of each test film layer region includes:
[0017] If the resistance after injection is equal to the resistance before injection, then no ions are injected into the test film layer area, and the ion injection barrier effect of the test film layer area meets the process requirements;
[0018] If the resistance after injection is smaller than the resistance before injection, ions are injected into the test film layer region, and the ion injection barrier effect of the test film layer region does not meet the process requirements.
[0019] Optionally, the sum of the thicknesses of the respective test film layer regions and the respective photoresist layer regions covering the test film layer regions is the same.
[0020] Optionally, forming the test film layer on the test wafer includes: forming the test film layer on the test wafer using an atomic layer deposition process.
[0021] Optionally, the step of forming a test film layer on the test wafer using an atomic layer deposition process includes:
[0022] Adding a first precursor into a deposition chamber and depositing it on the surface of the test wafer to form an initial precursor adsorption layer;
[0023] Repeatedly forming a plurality of stacked film layers of additional thickness in various regions above the initial precursor adsorption layer;
[0024] Among them, the thickness of the multiple additional thickness film layers stacked repeatedly formed in one area is the same, and the thickness of the multiple additional thickness film layers stacked repeatedly formed in different areas is different. The initial precursor adsorption layer and the multiple additional thickness film layers in different areas constitute the multiple test film layer areas with different thicknesses.
[0025] Optionally, the plurality of test film layer regions include at least a first test film layer region and a second test film layer region having different thicknesses;
[0026] The step of forming a film layer of additional thickness in each region above the initial precursor adsorption layer comprises:
[0027] introducing a first reaction gas into the deposition chamber to react with the initial precursor adsorption layer to form a film layer of initial thickness;
[0028] Adding a first precursor into the deposition chamber and depositing the first precursor in the first test film layer region above the initial thickness film layer to form a first precursor adsorption layer;
[0029] Adding a second precursor into the deposition chamber to deposit a second precursor adsorption layer in the second test film layer region above the initial thickness film layer, so as to form a film layer of additional thickness in the second test film layer region;
[0030] introducing a second reaction gas to react with the first precursor adsorption layer to form a film layer of intermediate thickness;
[0031] The first precursor is continuously added into the deposition chamber to form the first precursor adsorption layer above the intermediate thickness film layer, so as to form an additional thickness film layer in the first test film layer region.
[0032] Optionally, also include:
[0033] The step of forming an additional thickness film layer in each area above the initial precursor adsorption layer is repeatedly performed until the thickness difference between the first test film layer area and the second test film layer area reaches a target difference.
[0034] Optionally, the first precursor is silicon, the second precursor is hafnium, the first reaction gas is oxygen, and the second reaction gas is nitrogen.
[0035] Optionally, the method for measuring the resistance before injection and the resistance after injection of each test film layer region includes: a four-probe test method.
[0036] In a second aspect, an embodiment of the present application provides a test structure for a photoresist layer, comprising:
[0037] Test wafers;
[0038] a test film layer located above the test wafer, the test film layer comprising at least a plurality of test film layer regions with different thicknesses;
[0039] a photoresist layer located above the test film layer, the photoresist layer comprising at least a plurality of photoresist layer regions of different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region correspondingly covers one test film layer region;
[0040] The photoresist layer is removed after ion implantation on the test wafer, and the pre-implantation resistance of each test film layer region measured before ion implantation on the test wafer and the post-implantation resistance of each test film layer region measured after ion implantation on the test wafer are used to determine the ion implantation blocking effect of each test film layer region. The photoresist layer region corresponding to the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region, and the minimum thickness among the target photoresist layer regions is the thickness of the photoresist layer used in the actual process.
[0041] It can be seen that the test method of the photoresist layer provided in the embodiment of the present application forms a photoresist layer on the test film layers of different thicknesses by forming test film layer regions of different thicknesses on the test wafer, wherein the photoresist layer at least includes a plurality of photoresist layer regions of different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region corresponds to covering one test film layer region, and at the same time, by measuring the pre-injection resistance of each test film layer region before ion implantation, and measuring the post-injection resistance of each test film layer region after ion implantation and removal of the photoresist layer, the ion implantation blocking effect of each test film layer region can be determined based on the pre-injection resistance and post-injection resistance of each test film layer region. The photoresist layer region covered by the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region, and the minimum thickness among the target photoresist layer regions can be determined as the thickness of the photoresist layer used in the actual process. Therefore, the photoresist layer testing method provided in the embodiment of the present application can test the thickness of the photoresist layer selected for blocking ion implantation, thereby providing support for reducing the influence of the photoresist layer on the CD of the ion implantation region. At the same time, the testing method provided in the embodiment of the present application can implement testing of multiple photoresist layer regions with different thicknesses on the same test wafer, thereby reducing the number of test wafers used for testing and lowering the testing cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.
[0043] Figure 1 This is a flow chart of a method for testing a photoresist layer provided in an embodiment of the present application;
[0044] Figures 2 to 11 It is a schematic diagram of the test structure corresponding to each step in the test method provided in the embodiment of the present application. DETAILED DESCRIPTION
[0045] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.
[0046] In semiconductor manufacturing, ion implantation (IMP) is a core process for precisely controlling the electrical properties of materials (such as doping concentration and conductivity type). There are multiple ion implantation-related steps in the semiconductor process. Due to the complex distribution of chip functional areas, photoresist, as a dynamic mask for ion implantation, can achieve precise spatial control of the ion beam by selectively blocking or exposing the target area. In other words, before ion implantation is performed on part of the wafer, photoresist is needed to block the areas of the wafer that do not require ion implantation. This photoresist that selectively blocks ion implantation is considered a temporary protective layer, which can be called a photoresist layer.
[0047] However, during the actual formation of the photoresist layer, a photoresist layer that is too thin may not completely block ion implantation, resulting in unintended implantation in areas that should be blocked, damaging device performance. A photoresist layer that is too thick may affect the CD (critical dimension) of the ion implantation area. Specifically, during the photolithography process, an excessively thick photoresist layer may increase light scattering (e.g., diffraction or reflection) in the photoresist layer, resulting in blurred edges of the exposed pattern. Consequently, after development, the actual pattern CD may deviate from the designed value. Therefore, it is necessary to select a photoresist layer of accurate thickness to block ion implantation and minimize the impact on the CD of the ion implantation area.
[0048] A testing scheme for a photoresist layer is as follows: multiple test silicon wafers are provided, photoresist layers of different thicknesses are coated on different test silicon wafers, ions of a certain energy are injected into the silicon wafers coated with the photoresist layers of different thicknesses, the photoresist layers of each silicon wafer are removed, and finally each silicon wafer is tested using secondary ion mass spectrometry to obtain the ion quantity of each silicon wafer. When the ion quantity on the silicon wafer is within an allowable range, it is considered that the thickness of the photoresist layer corresponding to the silicon wafer with the ion quantity is appropriate; otherwise, it is considered that the thickness of the photoresist layer corresponding to the silicon wafer with the ion quantity is inappropriate.
[0049] Although the above solution can test the blocking effect of photoresist layers of different thicknesses on ion implantation, it consumes a large amount of test silicon wafers and is costly, and the secondary ion mass spectrometry test is expensive.
[0050] In view of this, an embodiment of the present application provides a method for testing a photoresist layer, which can test the thickness of a photoresist layer selected for blocking ion implantation, thereby providing support for reducing the impact of the photoresist layer on the CD of the ion implantation area.
[0051] Figure 1 This is a flow chart of a method for testing a photoresist layer provided in an embodiment of the present application. Figures 2 to 11 Schematic diagram of the test structure corresponding to each step of the test method provided in the embodiment of the present application, such as Figure 1 As shown, the method includes the following steps.
[0052] Step S1: providing a test wafer.
[0053] like Figure 2 As shown, the test wafer 100 provides a process basis for the subsequent formation of test film layer areas and photoresist layer areas of different thicknesses; in the embodiment of the present application, the test of photoresist layer areas of different thicknesses can be achieved on the same test wafer, thereby reducing the test cost.
[0054] Step S2: forming a test film layer on the test wafer, wherein the test film layer includes at least a plurality of test film layer regions with different thicknesses.
[0055] In the embodiment of the present application, the sum of the thicknesses of the respective test film layer regions and the respective photoresist layer regions covering the test film layer regions is the same.
[0056] Therefore, in order to form photoresist layer regions with different thicknesses and to test the photoresist layer regions with different thicknesses, a plurality of test film layer regions with different thicknesses may be formed on the test wafer first.
[0057] In an optional implementation, the method of forming the test film layer on the test wafer includes: forming the test film layer on the test wafer using an atomic layer deposition (ALD) process.
[0058] The atomic layer deposition process is a thin film deposition method that can deposit materials layer by layer on the surface of a wafer in the form of a single atomic film. By alternately introducing precursors and reaction gases, materials are grown layer by layer on the surface of the wafer. Its advantages lie in precise thickness control, excellent uniformity and conformality. Therefore, the embodiment of the present application adopts the atomic layer deposition process to form multiple test film layer areas with different thicknesses on the test wafer.
[0059] The following combination Figures 3 to 10 , the specific steps of using the atomic layer deposition process to form multiple test film layer areas with different thicknesses on the test wafer are described in detail.
[0060] Reference Figure 3, adding a first precursor into the deposition chamber, and depositing it on the surface of the test wafer 100 to form an initial precursor adsorption layer 201 .
[0061] In a specific implementation, a first precursor may be added into a deposition chamber where an atomic layer deposition process is performed, and the first precursor forms a chemically adsorbed initial precursor adsorption layer 201 on the surface of the test wafer.
[0062] In an optional embodiment, the first precursor may be silicon (Si).
[0063] In other embodiments, the first precursor may also be a material that does not easily react with nitrogen (N), such as zirconium (Zr) and tantalum (Ta).
[0064] Further, if Figures 4 to 9 As shown, multiple stacked film layers of additional thickness are repeatedly formed in various regions above the initial precursor adsorption layer 201;
[0065] Among them, the thickness of the multiple additional thickness film layers stacked repeatedly formed in one area is the same, and the thickness of the multiple additional thickness film layers stacked repeatedly formed in different areas is different. The initial precursor adsorption layer 201 and the multiple additional thickness film layers in different areas constitute the multiple test film layer areas with different thicknesses.
[0066] That is to say, a plurality of regions are divided above the initial precursor adsorption layer 201, corresponding to the plurality of test film layer regions finally formed, wherein a plurality of additional thickness film layers are repeatedly stacked in one region, and the thickness of each additional thickness film layer is the same; while for different regions, the thickness of the plurality of additional thickness film layers repeatedly stacked in different regions is different; the thickness of a test film layer region is composed of the thickness of the initial precursor adsorption layer and the thickness of the plurality of additional thickness film layers stacked in the region, so the thickness of each test film layer region finally formed is different.
[0067] For ease of explanation, the embodiment of the present application is described by taking the formation of two test film layer areas with different thicknesses as an example.
[0068] In an optional implementation, the plurality of test film layer areas include at least a first test film layer area A1 and a second test film layer area A2 having different thicknesses.
[0069] The steps of forming a film layer of additional thickness in each region above the initial precursor adsorption layer 201 include the following steps.
[0070] Reference Figure 4 , a first reaction gas is introduced into the deposition chamber to react with the initial precursor adsorption layer 201 to form a film layer 202 of initial thickness.
[0071] In an embodiment of the present application, the first reaction gas may be oxygen (O2). During the reaction, O atoms chemically bond with Si in the initial precursor adsorption layer 201 to form an initial thickness film layer 202, namely a SiO2 film layer.
[0072] Reference Figure 5 , a first precursor (eg Si) is added into the deposition chamber, and a first precursor adsorption layer 211 is deposited in the first test film layer area A1 above the initial thickness film layer 202 .
[0073] It can be understood that in this step, the content of the first precursor added to the deposition chamber is less than the content of the first precursor added to the deposition chamber in the step of depositing the initial precursor adsorption layer 201 on the surface of the test wafer 100, so that the first precursor adsorption layer 211 can be formed only in the first test film layer area A1.
[0074] Reference Figure 6 as well as Figure 9 , adding a second precursor into the deposition chamber, and depositing a second precursor adsorption layer 221 in the second test film layer area A2 above the initial thickness film layer 202 to form an additional thickness film layer 222 in the second test film layer area A2.
[0075] In a specific implementation, a second precursor may be added into the deposition chamber, and the second precursor forms a chemically adsorbed second precursor adsorption layer 221 on the surface of the second test film layer area A2 of the initial thickness film layer 202 .
[0076] In an optional embodiment, the second precursor may be hafnium (Hf).
[0077] In other embodiments, the first precursor may also be a material that does not easily react with nitrogen (N), such as zirconium (Zr) and tantalum (Ta).
[0078] Thus, an additional thickness film layer 222 is formed in the second test film region A2.
[0079] Further, if Figure 7 and Figure 8 As shown, after forming an additional thickness film layer 222 in the second test film layer area A2 , an additional thickness film layer is formed in the first test film layer area A1 .
[0080] Specifically, refer to Figure 7 , a second reaction gas is introduced to react with the first precursor adsorption layer 211 to form a film layer 212 of intermediate thickness.
[0081] In an optional embodiment, the second reaction gas may be nitrogen (N 2 ). During the reaction process, N atoms chemically bond with Si in the first precursor adsorption layer 211 to form a film layer 212 of intermediate thickness.
[0082] Reference Figure 8 as well as Figure 9 , continue to add the first precursor (such as Si) into the deposition chamber to form the first precursor adsorption layer above the intermediate thickness film layer 212 to form an additional thickness film layer 213 in the first test film layer area A1.
[0083] Thus, an additional thickness film layer 213 is formed in the first test film layer area A1.
[0084] like Figure 8 As shown, since the steps of forming an additional thickness film layer in the first test film layer area and forming an additional thickness film layer in the second test film layer area are different, and the materials used in the formation process are also different (such as the first precursor and the second precursor), the thickness of the additional thickness film layer in the first test film layer area and the additional thickness film layer in the second test film layer area are different.
[0085] Furthermore, the above steps may be repeated in order to achieve a desired target thickness difference between different test film regions.
[0086] Specifically, refer to Figure 9 as well as Figure 10 Repeat the step of forming the additional thickness film layer in each area above the initial precursor adsorption layer 201 until the thickness difference between the first test film layer area A1 and the second test film layer area A2 reaches the target difference.
[0087] At this point, multiple test film regions with different thicknesses are formed on the test wafer, such as Figure 10 The first test film layer area A1 and the second test film layer area A2 are shown, and the multiple test film layer areas constitute the test film layer 200 .
[0088] Step S3: measuring the resistance of each test film region before injection.
[0089] In an embodiment of the present application, in order to test the blocking effect of photoresist layers of different thicknesses on ion implantation, the resistance of each test film region covered by the photoresist layer can be measured, including the resistance before ion implantation and the resistance after ion implantation. The resistance before implantation is compared with the resistance after implantation to further analyze the effect of ion implantation.
[0090] In an optional implementation, a four-probe test method may be used to measure the pre-implantation resistance RS1 of each test film layer region.
[0091] Step S4: forming a photoresist layer on the test film layer, wherein the photoresist layer at least includes a plurality of photoresist layer regions with different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region correspondingly covers one test film layer region.
[0092] After forming multiple test film layer areas with different thicknesses, multiple photoresist layer areas can be formed on the test film layer to cover the multiple test film layer areas. Since the sum of the thicknesses of the test film layer areas and the photoresist layer areas covering the test film layer areas is the same, the multiple photoresist layer areas have different thicknesses, thereby enabling testing of photoresist layers with different thicknesses.
[0093] In an optional embodiment, if Figure 11 As shown, a photoresist layer 300 is formed on the test film layer 200. The photoresist layer 300 includes at least a plurality of photoresist layer regions of different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region corresponds to covering one test film layer region, for example, a photoresist layer region B1 covering the first test film layer region, and a photoresist layer region B2 covering the second test film layer region.
[0094] In an optional implementation, after the photoresist layer is formed, a step profiler or an optical microscope may be used to measure and record the thickness of each photoresist layer region, so as to subsequently determine the thickness of the photoresist layer used in the actual process.
[0095] Step S5: performing ion implantation on the test wafer on which the photoresist layer is formed, and then removing the photoresist layer.
[0096] In the specific implementation, such as Figure 11 As shown, ions of a determined energy / dose may be implanted onto the test wafer on which the photoresist layer is formed, and then the photoresist layer is removed to measure the post-implantation resistance of each test film region after the ion implantation.
[0097] Step S6: measuring the post-implantation resistance of each test film region.
[0098] In an optional implementation, a four-probe test method may be used to measure the post-implantation resistance RS2 of each test film layer region.
[0099] Step S7: Determine the ion implantation blocking effect of each test film layer area based on the pre-injection resistance and post-injection resistance of each test film layer area, wherein the photoresist layer area covered by the test film layer area whose ion implantation blocking effect meets the process requirements is the target photoresist layer area.
[0100] In the embodiment of the present application, since the resistance of the test film layer area is inversely proportional to the ion implantation dose, that is, the greater the ion implantation dose, the smaller the resistance of the test film layer area, the ion implantation blocking effect of each test film layer area can be judged based on this.
[0101] In an optional implementation, if the resistance RS2 after injection is equal to the resistance RS2 before injection, no ions are injected into the test film layer area, and the ion injection barrier effect of the test film layer area meets the process requirements.
[0102] That is to say, if the resistance of the test film layer area before injection and the resistance after injection do not change, it indicates that no ions are injected into the test film layer area during the ion injection process, and the ion injection blocking effect of the test film layer area can meet the process requirements, then the corresponding photoresist layer area covering the test film layer area can completely block the ion injection.
[0103] If the resistance RS2 after injection is smaller than the resistance RS1 before injection, ions are injected into the test film layer region, and the ion injection barrier effect of the test film layer region does not meet the process requirements.
[0104] That is to say, if the resistance of the test film layer area after injection is less than the resistance before injection, it indicates that ions are injected into the test film layer area during the ion injection process, and the ion injection blocking effect of the test film layer area does not meet the process requirements, then the corresponding photoresist layer area covering the test film layer area cannot completely block the ion injection.
[0105] In the embodiment of the present application, the photoresist layer region covered by the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region.
[0106] Step S8: determining the minimum thickness among the thicknesses of the target photoresist layer region as the thickness of the photoresist layer used in the actual process.
[0107] In the embodiment of the present application, the thickness of the photoresist layer region covered by the test film layer region where the ion implantation blocking effect meets the process requirements, i.e., the thickness of the target photoresist layer region, is the thickness of the photoresist layer region that can completely block ion implantation. Furthermore, on the basis of being able to completely block ion implantation, in order to avoid the influence of an excessively thick photoresist layer on the CD of the ion implantation region, the minimum thickness among the target photoresist layer regions can be determined as the thickness of the photoresist layer used in the actual process.
[0108] It can be seen that the test method of the photoresist layer provided in the embodiment of the present application forms a photoresist layer on the test film layers of different thicknesses by forming test film layer regions of different thicknesses on the test wafer, wherein the photoresist layer at least includes a plurality of photoresist layer regions of different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region corresponds to covering one test film layer region, and at the same time, by measuring the pre-injection resistance of each test film layer region before ion implantation, and measuring the post-injection resistance of each test film layer region after ion implantation and removal of the photoresist layer, the ion implantation blocking effect of each test film layer region can be determined based on the pre-injection resistance and post-injection resistance of each test film layer region. The photoresist layer region covered by the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region, and the minimum thickness among the target photoresist layer regions can be determined as the thickness of the photoresist layer used in the actual process. Therefore, the photoresist layer testing method provided in the embodiment of the present application can test the thickness of the photoresist layer selected for blocking ion implantation, thereby providing support for reducing the influence of the photoresist layer on the CD of the ion implantation region. At the same time, the testing method provided in the embodiment of the present application can implement testing of multiple photoresist layer regions with different thicknesses on the same test wafer, thereby reducing the number of test wafers used for testing and lowering the testing cost.
[0109] In a further optional implementation, the embodiment of the present application further provides a test structure of the photoresist layer, referring to Figure 11 , the test structure includes:
[0110] Test wafer 100;
[0111] A test film layer 200 located above the test wafer 100 , wherein the test film layer includes at least a plurality of test film layer regions with different thicknesses;
[0112] a photoresist layer 300 located above the test film layer 200, the photoresist layer comprising at least a plurality of photoresist layer regions of different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region correspondingly covers one test film layer region;
[0113] The photoresist layer is removed after ion implantation on the test wafer, and the pre-implantation resistance of each test film layer region measured before ion implantation on the test wafer and the post-implantation resistance of each test film layer region measured after ion implantation on the test wafer are used to determine the ion implantation blocking effect of each test film layer region. The photoresist layer region corresponding to the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region, and the minimum thickness among the target photoresist layer regions is the thickness of the photoresist layer used in the actual process.
[0114] The above describes multiple embodiment schemes provided by the embodiments of the present application. The various optional methods introduced in each embodiment scheme can be combined and cross-referenced with each other without conflict, thereby extending a variety of possible embodiment schemes, which can all be considered as embodiment schemes disclosed and open in the embodiments of the present application.
[0115] Although the embodiments of the present application are disclosed above, the present application is not limited thereto. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims.
Claims
1. A method for testing a photoresist layer, characterized in that: include: Provide test wafers; forming a test film layer on the test wafer, wherein the test film layer comprises at least a plurality of test film layer regions with different thicknesses; Measure the pre-injection resistance of each test film area; forming a photoresist layer on the test film layer, wherein the photoresist layer at least includes a plurality of photoresist layer regions with different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region correspondingly covers one test film layer region; Performing ion implantation on the test wafer on which the photoresist layer is formed, and then removing the photoresist layer; Measure the post-implantation resistance of each test film area; Determine the ion implantation blocking effect of each test film layer region based on the pre-implantation resistance and post-implantation resistance of each test film layer region, wherein the photoresist layer region covered by the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region; The minimum thickness among the thicknesses of the target photoresist layer region is determined as the thickness of the photoresist layer used in the actual process.
2. The testing method according to claim 1, wherein: Determining the ion implantation blocking effect of each test film layer region according to the pre-injection resistance and the post-injection resistance of each test film layer region includes: If the resistance after injection is equal to the resistance before injection, then no ions are injected into the test film layer area, and the ion injection barrier effect of the test film layer area meets the process requirements; If the resistance after injection is smaller than the resistance before injection, ions are injected into the test film layer region, and the ion injection barrier effect of the test film layer region does not meet the process requirements.
3. The testing method according to claim 1, wherein: The sum of the thicknesses of the test film layer regions and the photoresist layer regions covering the test film layer regions is the same.
4. The testing method according to claim 1, wherein: The forming of the test film layer on the test wafer includes: forming the test film layer on the test wafer by adopting an atomic layer deposition process.
5. The testing method according to claim 4, characterized in that: The step of forming a test film layer on the test wafer by using an atomic layer deposition process includes: Adding a first precursor into a deposition chamber and depositing it on the surface of the test wafer to form an initial precursor adsorption layer; Repeatedly forming a plurality of stacked film layers of additional thickness in various regions above the initial precursor adsorption layer; Among them, the thickness of the multiple additional thickness film layers stacked repeatedly formed in one area is the same, and the thickness of the multiple additional thickness film layers stacked repeatedly formed in different areas is different. The initial precursor adsorption layer and the multiple additional thickness film layers in different areas constitute the multiple test film layer areas with different thicknesses.
6. The testing method according to claim 5, characterized in that: The plurality of test film layer regions include at least a first test film layer region and a second test film layer region with different thicknesses; The step of forming a film layer of additional thickness in each region above the initial precursor adsorption layer comprises: introducing a first reaction gas into the deposition chamber to react with the initial precursor adsorption layer to form a film layer of initial thickness; Adding a first precursor into the deposition chamber and depositing the first precursor in the first test film layer region above the initial thickness film layer to form a first precursor adsorption layer; Adding a second precursor into the deposition chamber to deposit a second precursor adsorption layer in the second test film layer region above the initial thickness film layer, so as to form a film layer of additional thickness in the second test film layer region; introducing a second reaction gas to react with the first precursor adsorption layer to form a film layer of intermediate thickness; The first precursor is continuously added into the deposition chamber to form the first precursor adsorption layer above the intermediate thickness film layer, so as to form an additional thickness film layer in the first test film layer region.
7. The testing method according to claim 6, characterized in that: Also includes: The step of forming an additional thickness film layer in each area above the initial precursor adsorption layer is repeatedly performed until the thickness difference between the first test film layer area and the second test film layer area reaches a target difference.
8. The testing method according to claim 6, wherein: The first precursor is silicon, the second precursor is hafnium, the first reaction gas is oxygen, and the second reaction gas is nitrogen.
9. The testing method according to claim 1, wherein: The method for measuring the resistance before injection and the resistance after injection of each test film layer area includes: a four-probe test method.
10. A test structure for a photoresist layer, characterized in that: include: Test wafers; a test film layer located above the test wafer, the test film layer comprising at least a plurality of test film layer regions with different thicknesses; a photoresist layer located above the test film layer, the photoresist layer comprising at least a plurality of photoresist layer regions of different thicknesses covering the plurality of test film layer regions, wherein one photoresist layer region correspondingly covers one test film layer region; The photoresist layer is removed after ion implantation on the test wafer, and the pre-implantation resistance of each test film layer region measured before ion implantation on the test wafer and the post-implantation resistance of each test film layer region measured after ion implantation on the test wafer are used to determine the ion implantation blocking effect of each test film layer region. The photoresist layer region corresponding to the test film layer region whose ion implantation blocking effect meets the process requirements is the target photoresist layer region, and the minimum thickness among the target photoresist layer regions is the thickness of the photoresist layer used in the actual process.