Adjustable photolithographic process parameter feedback method and system

Abstract

The invention discloses an adjustable photolithographic process parameter feedback method and system, and belongs to the technical field of semiconductors, and the adjustable photolithographic process parameter feedback method comprises the following steps: marking wafers according to production batches, and recording process parameters and critical dimensions when the current batch of wafers execute a first film layer, the process parameters comprise delivery values; obtaining the deviation between the delivery value and the critical dimension of the current batch of wafers, and adjusting the critical dimension and the corresponding exposure parameter of the second film layer; wherein the first film layer and the second film layer are patterned photoresist layers, and at least parts of areas defined by the first film layer and the second film layer are adjacent to each other. The key size of the second film layer is adjusted by obtaining the deviation between the key size of the first film layer and the delivery value, the influence of the edge of the first film layer on the pattern of the second film layer is reduced, and the stable product performance is maintained.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an adjustable photolithography process parameter feedback method and system. Background Art

[0002] In the photolithography process of semiconductor devices, the critical dimensions (CD) of the front and back layers are strongly correlated, which will affect the yield and performance of the product. Figure 1 and Figure 2 As shown, the grating spacing size of the first film layer after exposure determines the position of the subsequent process compound sidewall. Relatively speaking, after the subsequent second film layer is exposed, the photoresist boundary needs to fall on the sidewall square. Figure 3 As shown in FIG. 1 , if the critical dimension of the second film layer is too large, silicon residue will be left after etching. Figure 4 and Figure 5 As shown, if it is too small, it will cause damage to the aluminum surface and produce defects, such as Figure 6 and Figure 7 shown.

[0003] Among them, the existing photolithography system can generally only feedback the energy of the current layer according to the lower value of the critical dimension of the current film layer, and the parameter feedback between different film layers is independent. When the lower value of the critical dimension of the first film layer changes, the sidewall position moves. If the second film layer is still exposed at the originally preset critical dimension, it will lead to the above-mentioned product yield and defects.

[0004] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0005] The object of the present invention is to provide an adjustable photolithography process parameter feedback method and system to solve the problems of silicon residue and aluminum damage.

[0006] In order to solve the above technical problems, the present invention provides an adjustable lithography process parameter feedback method, comprising the following steps:

[0007] Mark the wafers according to the production batch, and record the process parameters and key dimensions of the first film layer of the current batch of wafers, wherein the process parameters include the value of the goods;

[0008] Obtain the deviation between the shipping value and the critical dimension of the current batch of wafers, and adjust the critical dimension and corresponding exposure parameters of the second film layer; wherein the first film layer and the second film layer are both patterned photoresist layers and the areas defined by the two are at least partially adjacent.

[0009] Preferably, obtaining the deviation between the order value and the critical dimension of the current batch of wafers includes: subtracting the order value and the critical dimension of the current batch to calculate the deviation.

[0010] Preferably, adjusting the critical dimension of the second film layer and the corresponding exposure parameters includes: adding the deviation to the critical dimension of the second film layer to obtain the adjusted critical dimension of the second film layer, and obtaining the adjusted exposure parameters of the second film layer through the relationship between the exposure parameters and the critical dimension, and feeding back the exposure parameters to the exposure machine.

[0011] Preferably, the process parameters required for the first film layer of the next batch of wafers are also adjusted based on the deviation.

[0012] Preferably, the process parameters also include exposure energy and focal length of the first film layer of the current batch of wafers.

[0013] Based on the same technical concept, the present disclosure also provides an adjustable photolithography process parameter feedback system, including:

[0014] A marking module is used to mark wafers according to production batches;

[0015] A recording module, used to record the process parameters and key dimensions of the first film layer of the current batch of wafers, wherein the process parameters include the value of the goods;

[0016] A calculation module is used to obtain the deviation between the order value and the critical dimension of the current batch of wafers;

[0017] An execution module, configured to adjust a critical dimension of the second film layer and a corresponding exposure parameter based on the deviation;

[0018] Wherein, both the first film layer and the second film layer are patterned photoresist layers and the areas defined by the two layers are at least partially adjacent.

[0019] Preferably, the calculation module obtains the deviation between the order value and the critical dimension of the current batch of wafers by: subtracting the order value and the critical dimension of the current batch to calculate the deviation.

[0020] Preferably, the execution module adjusts the critical dimension of the second film layer and the corresponding exposure parameter including: adding the deviation to the critical dimension of the second film layer to obtain the adjusted critical dimension of the second film layer, and obtaining the adjusted exposure parameter of the second film layer through the relationship between the exposure parameter and the critical dimension, and feeding back the exposure parameter to the exposure machine.

[0021] Preferably, the execution module further adjusts the process parameters required for the first film layer of the next batch of wafers based on the deviation.

[0022] Preferably, the process parameters also include exposure energy and focal length of the first film layer of the current batch of wafers.

[0023] In the adjustable lithography process parameter feedback method provided by the present invention, the deviation between the critical dimension of the first film layer and the lower value is obtained to adjust the critical dimension of the second film layer, thereby reducing the influence of the edge of the first film layer on the pattern of the second film layer and maintaining stable product performance.

[0024] The adjustable lithography process parameter feedback system provided by the present invention and the adjustable lithography process parameter feedback method provided by the present invention belong to the same inventive concept. Therefore, the adjustable lithography process parameter feedback system provided by the present invention at least has all the advantages of the adjustable lithography process parameter feedback method provided by the present invention, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0026] Figure 1 is a schematic diagram of photolithography of the first film layer in the prior art;

[0027] Figure 2 It is a schematic diagram of a compound side wall after photolithography of the first film layer in the prior art;

[0028] Figure 3 is a schematic diagram of photolithography of the second film layer in the prior art;

[0029] Figure 4 This is a schematic diagram of the critical dimension of the second film layer being too large in the prior art;

[0030] Figure 5 It is a schematic diagram of silicon residue phenomenon in the prior art;

[0031] Figure 6 This is a schematic diagram showing that the critical dimension of the second film layer in the prior art is too small;

[0032] Figure 7 It is a schematic diagram of aluminum damage phenomenon in the prior art;

[0033] Figure 8 is an execution flow chart of an embodiment of the present invention;

[0034] Fig. 9 is a system architecture diagram of an embodiment of the present invention;

[0035] Figure 10a-Figure 10b It is a schematic diagram comparing the second film layer of the prior art and the second film layer of the present invention when the value of the first film layer is reduced under the critical size;

[0036] Figure 11a-Figure 11bIt is a schematic diagram comparing the second film layer of the prior art and the second film layer of the present invention when the value of the first film layer is increased under the critical size.

[0037] In the attached figure:

[0038] 10. Photoresist; 11. SiCN; 12. Oxide layer; 13. SiN; 14. HfO; 15. Bottom anti-reflective coating; 16. NSG; 17. Silicon; 18. Substrate; 19. TiN; 20. TaN; 21. Aluminum. DETAILED DESCRIPTION

[0039] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0040] As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features. The term "proximal end" is usually the end close to the operator, and the term "distal end" is usually the end close to the patient. "One end" and "the other end" as well as "proximal end" and "distal end" usually refer to two corresponding parts, which include not only the endpoints. The terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of the two elements or the interaction relationship between the two elements. In addition, as used in the present invention, an element is arranged on another element, which usually only means that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and it cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any position such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The inventors have found that Figure 1 A semiconductor device structure is provided, wherein SiN13, SiCN11, silicon 17, SiCN11 and SiN13 are formed on a substrate 18 from left to right, and NSG16 (Nondoped SilicateGlass, silicate glass without infiltration of impurities) is also formed in SiN13, an oxide layer 12 and HfO14 are also provided between silicon 17 and substrate 18, an oxide layer 12 is also formed on the surface of substrate 18, a first film layer is formed on the oxide layer 12, the first film layer includes a photoresist 10 and a bottom anti-reflective coating 15 (BARC), after some devices at the bottom of substrate 18 are formed by the first film layer, such as Figure 2 If the PMOS is formed in the subsequent process, the area defined by the first film layer will obviously affect the subsequent devices. The edge of the pattern after the first film layer is exposed needs to fall on the side wall. If the grating spacing of the first film layer is small, the grating line width of the second film layer will be large, resulting in silicon residue. Figure 4 and Figure 5 If the grating spacing of the first film layer is larger, the line width of the grating of the second film layer will be smaller, resulting in aluminum damage.

[0042] Based on this, the core idea of ​​the present invention is to adjust the key size of the second film layer by obtaining the deviation between the key size of the first film layer and the lower value, thereby reducing the influence of the edge of the first film layer on the pattern of the second film layer and maintaining stable product performance.

[0043] For details, please refer to Figure 8-11b , which is a schematic diagram of an embodiment of the present invention. Figure 8 As shown, an adjustable photolithography process parameter feedback method comprises the following steps:

[0044] S1, marking the wafers according to the production batches, and recording the process parameters and key dimensions of the first film layer of the current batch of wafers, wherein the process parameters include the shipment value.

[0045] In one embodiment, each batch of wafers is marked, and the process parameters and critical dimensions of the marked batch of wafers reaching a certain film layer are recorded, and the order value is specifically the order value of the critical dimension. The process parameters also include the exposure energy and focal length of the first film layer of the current batch of wafers. Furthermore, the exposure energy and focal length of the first film layer of the next batch of wafers, as well as the exposure energy and focal length of the first film layer adjusted based on the following deviations, can also be stored and recorded.

[0046] It can be understood that both the first film layer and the second film layer are photoresists, which can be polyimide (PI:polyimide), benzocyclobutene (BCB:bis-BenzoCycloButene), polyparaphenylenebenzobisoxazole (PBO:P-phenylene-2,6-BenzobisOxazole), and are not specifically limited to positive photoresists and negative photoresists, which can be selected according to the process. After photolithography exposure, a patterned first film layer is formed, and then the lower value and critical size thereof are obtained.

[0047] S2, obtaining the deviation between the shipping value and the critical dimension of the current batch of wafers, and adjusting the critical dimension and corresponding exposure parameters of the second film layer; wherein the first film layer and the second film layer are both patterned photoresist layers and the areas defined by the two are at least partially adjacent.

[0048] Specifically, obtaining the deviation between the order value and the critical dimension of the current batch of wafers includes: subtracting the order value and the critical dimension of the current batch to calculate the deviation.

[0049] Wherein, adjusting the critical dimension of the second film layer and the corresponding exposure parameter includes: adding the deviation to the critical dimension of the second film layer to obtain the adjusted critical dimension of the second film layer, and obtaining the adjusted exposure parameter of the second film layer through the relationship between the exposure parameter and the critical dimension, and feeding back the exposure parameter to the exposure machine. The exposure parameter includes exposure energy and focal length. There is a certain relationship between the exposure parameter and the critical dimension.

[0050] Exemplarily, the process parameters required for the first film layer of the next batch of wafers are also adjusted based on the deviation. The exposure energy, focal length and critical dimensions of the next batch are adjusted according to the obtained deviation, thereby reducing the deviation of each batch of wafers.

[0051] For example Fig.10a As shown in FIG. 1 , when the first film layer's delivery value is less than the required target critical dimension, in the prior art, the original target critical dimension at the red line of the second film layer and the actual required critical dimension at the blue line are the same. In the present method, by calculating the deviation between the delivery value of the first film layer and the actual critical dimension, the original target critical dimension of the second film layer is subtracted from the deviation to obtain the following: Fig.10b The second film layer after adjustment.

[0052] For example Fig.11a As shown in FIG. 1 , when the first film layer's delivery value is greater than the required target critical dimension, in the prior art, the original target critical dimension at the red line of the second film layer and the actual required critical dimension at the blue line are the same. In the present method, by calculating the deviation between the delivery value of the first film layer and the actual critical dimension, the original target critical dimension of the second film layer is added with the deviation value, and the result is as follows: Fig.11b The second film layer after adjustment.

[0053] Based on the same technical concept, such as Fig. 9 As shown, the present disclosure also provides an adjustable photolithography process parameter feedback system, comprising:

[0054] The marking module P1 is used to mark the wafers according to the production batch;

[0055] Recording module P2, used to record the process parameters and key dimensions of the first film layer of the current batch of wafers, wherein the process parameters include the value of the goods;

[0056] Calculation module P3, used to obtain the deviation between the order value and the critical dimension of the current batch of wafers;

[0057] The execution module P4 is used to adjust the critical dimension and corresponding exposure parameter of the second film layer based on the deviation; wherein the first film layer and the second film layer are both patterned photoresist layers and the areas defined by the two are at least partially adjacent.

[0058] In one embodiment, each batch of wafers is marked, and the process parameters and critical dimensions of the marked batch of wafers reaching a certain film layer are recorded, and the order value is specifically the order value of the critical dimension. The process parameters also include the exposure energy and focal length of the first film layer of the current batch of wafers. Furthermore, the exposure energy and focal length of the first film layer of the next batch of wafers, as well as the exposure energy and focal length of the first film layer adjusted based on the following deviations, can also be stored and recorded.

[0059] It can be understood that both the first film layer and the second film layer are photoresists, which can be polyimide (PI:polyimide), benzocyclobutene (BCB:bis-BenzoCycloButene), polyparaphenylenebenzobisoxazole (PBO:P-phenylene-2,6-BenzobisOxazole), and are not specifically limited to positive photoresists and negative photoresists, which can be selected according to the process. After photolithography exposure, a patterned first film layer is formed, and then the lower value and critical size thereof are obtained.

[0060] Specifically, the calculation module P3 obtains the deviation between the order value and the critical dimension of the current batch of wafers by: subtracting the order value and the critical dimension of the current batch to calculate the deviation.

[0061] Specifically, the execution module P4 adjusts the critical dimension of the second film layer and the corresponding exposure parameter by: adding the deviation to the critical dimension of the second film layer to obtain the adjusted critical dimension of the second film layer, and obtaining the adjusted exposure parameter of the second film layer through the relationship between the exposure parameter and the critical dimension, and feeding back the exposure parameter to the exposure machine. The execution module P4 also adjusts the process parameters required for the first film layer of the next batch of wafers based on the deviation.

[0062] Specifically, the process parameters also include exposure energy and focal length of the first film layer of the current batch of wafers.

[0063] Wherein, adjusting the critical dimension of the second film layer and the corresponding exposure parameter includes: adding the deviation to the critical dimension of the second film layer to obtain the adjusted critical dimension of the second film layer, and obtaining the adjusted exposure parameter of the second film layer through the relationship between the exposure parameter and the critical dimension, and feeding back the exposure parameter to the exposure machine. The exposure parameter includes exposure energy and focal length. There is a certain relationship between the exposure parameter and the critical dimension.

[0064] Exemplarily, the process parameters required for the first film layer of the next batch of wafers are also adjusted based on the deviation. The exposure energy, focal length and critical dimensions of the next batch are adjusted according to the obtained deviation, thereby reducing the deviation of each batch of wafers.

[0065] It should be understood that the above-mentioned device embodiments are only illustrative, and the device of the present disclosure can also be implemented in other ways. For example, the division of units / modules described in the above-mentioned embodiments is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units, modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0066] In addition, unless otherwise specified, each functional unit / module in each embodiment of the present disclosure may be integrated into one unit / module, or each unit / module may exist physically separately, or two or more units / modules may be integrated together. The above-mentioned integrated unit / module may be implemented in the form of hardware or in the form of a software program module.

[0067] The above description is only a description of the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. An adjustable lithography process parameter feedback method, characterized in that: The following steps are involved: Mark the wafers according to the production batch, and record the process parameters and key dimensions of the first film layer of the current batch of wafers, wherein the process parameters include the value of the goods; Obtain the deviation between the shipping value and the critical dimension of the current batch of wafers, and adjust the critical dimension and corresponding exposure parameters of the second film layer; wherein the first film layer and the second film layer are both patterned photoresist layers and the areas defined by the two are at least partially adjacent.

2. The adjustable photolithography process parameter feedback method according to claim 1, characterized in that: Obtaining the deviation between the order value and the critical dimension of the current batch of wafers includes: subtracting the order value and the critical dimension of the current batch to calculate the deviation.

3. The adjustable photolithography process parameter feedback method according to claim 1, characterized in that: Adjusting the critical dimension of the second film layer and the corresponding exposure parameters includes: adding the deviation to the critical dimension of the second film layer to obtain the adjusted critical dimension of the second film layer, and obtaining the adjusted exposure parameters of the second film layer through the relationship between the exposure parameters and the critical dimension, and feeding back the exposure parameters to the exposure machine.

4. The adjustable photolithography process parameter feedback method according to claim 1, characterized in that: The process parameters required for the first film layer of the next batch of wafers are also adjusted based on the deviation.

5. The adjustable photolithography process parameter feedback method according to claim 1, characterized in that: The process parameters also include exposure energy and focal length of the first film layer of the current batch of wafers.

6. An adjustable photolithography process parameter feedback system, characterized in that: include: A marking module is used to mark wafers according to production batches; A recording module, used to record the process parameters and key dimensions of the first film layer of the current batch of wafers, wherein the process parameters include the value of the goods; A calculation module is used to obtain the deviation between the order value and the critical dimension of the current batch of wafers; An execution module, configured to adjust a critical dimension of the second film layer and a corresponding exposure parameter based on the deviation; Wherein, both the first film layer and the second film layer are patterned photoresist layers and the areas defined by the two layers are at least partially adjacent.

7. The adjustable photolithography process parameter feedback system according to claim 6, characterized in that: The calculation module obtains the deviation between the order value and the critical size of the current batch of wafers, including: subtracting the order value and the critical size of the current batch to calculate the deviation.

8. The adjustable photolithography process parameter feedback system according to claim 6, characterized in that: The execution module adjusts the critical dimension of the second film layer and the corresponding exposure parameter, including: adding the deviation to the critical dimension of the second film layer to obtain the adjusted critical dimension of the second film layer, and obtaining the adjusted exposure parameter of the second film layer through the relationship between the exposure parameter and the critical dimension, and feeding back the exposure parameter to the exposure machine.

9. The adjustable photolithography process parameter feedback system according to claim 6, characterized in that: The execution module further adjusts the process parameters required for the first film layer of the next batch of wafers based on the deviation.

10. The adjustable photolithography process parameter feedback system according to claim 6, characterized in that: The process parameters also include exposure energy and focal length of the first film layer of the current batch of wafers.

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