A mark and method for improving lithography overlay accuracy

Abstract

The application provides a mark and a method for improving overlay accuracy of photolithography, an overlay mark, a forbidden domain provided outside the overlay mark, the forbidden domain surrounding the overlay mark, a scribe lane, the overlay mark and the forbidden domain being located in the scribe lane, and the width of the forbidden domain being greater than 40 microns and less than the width of the scribe lane. The application increases the width of the forbidden domain of the overlay mark to improve the overlay accuracy of photolithography after epitaxy, the deformation of the overlay mark after epitaxy is stable and controllable, and the overlay data measured for multiple times is stable.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a marking and method for improving photolithographic registration accuracy. Background Technology

[0002] Epitaxial growth, a technique in integrated circuit manufacturing, involves depositing a thin single-crystal layer on a single-crystal substrate. Epitaxy provides device designers with significant flexibility in optimizing devices, such as controlling the doping thickness, concentration, and contour of the outer layer. As device performance demands increase, epitaxial thickness is gradually rising. However, pattern drift is an unavoidable phenomenon in epitaxial growth, affecting the alignment accuracy of subsequent photolithography and thus limiting its overlay precision. Therefore, minimizing or avoiding pattern drift after epitaxial growth is crucial for photolithography accuracy. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a marking and method for improving the accuracy of photolithography registration, so as to solve the problem of pattern drift in epitaxial growth that affects the accuracy of photolithography registration.

[0004] To achieve the above and other related objectives, the present invention provides a marking and method for improving photolithographic registration accuracy, comprising at least:

[0005] An overlay mark is provided; a forbidden zone is provided around the overlay mark; the forbidden zone surrounds the overlay mark;

[0006] The dicing groove; the overprinting mark and the prohibition field are located within the dicing groove;

[0007] The width of the forbidden region is greater than 40 μm and less than the width of the dicing groove.

[0008] Preferably, the outer shape of the overprinted mark is square.

[0009] Preferably, the outer shape of the forbidden region is a square, and the side length of the square is 40 μm.

[0010] Preferably, the overlay mark is used to measure the overlay accuracy of the epitaxial layer.

[0011] The present invention also provides a method for improving photolithography overlay accuracy, comprising at least:

[0012] Step 1: Provide an overlay mark, the overlay mark having a prohibition zone around its periphery; the prohibition zone surrounds the overlay mark; the overlay mark and the prohibition zone are located within the dicing groove; the width of the prohibition zone is greater than 40 μm and less than the width of the dicing groove;

[0013] Step 2: Provide a substrate and deposit an epitaxial layer on the substrate;

[0014] Step 3: Use a photomask equipped with the overlay marks, forbidden regions, and dicing grooves to measure the overlay accuracy of the epitaxial layer.

[0015] Preferably, the outer shape of the overprinted mark in step one is square.

[0016] Preferably, the outer shape of the forbidden region in step one is a square, and the side length of the square is 40 μm.

[0017] As described above, the marking and method for improving photolithographic registration accuracy of the present invention have the following beneficial effects: the present invention improves the photolithographic registration accuracy after epitaxy by increasing the forbidden region width of the overlay marking, the deformation of the overlay marking after epitaxy is stable and controllable, and the overlay data measured multiple times is stable. Attached Figure Description

[0018] Figure 1 The image shown is an SEM image of the markers used in this invention to improve photolithographic alignment accuracy.

[0019] Figure 2 The diagram shows the structure of the marker for improving photolithographic registration accuracy according to the present invention. Detailed Implementation

[0020] 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.

[0021] Please see Figures 1 to 2 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.

[0022] This invention provides a mark for improving photolithographic registration accuracy, comprising at least:

[0023] An overlay mark is provided; a forbidden zone is provided around the overlay mark; the forbidden zone surrounds the overlay mark;

[0024] The dicing groove; the overprinting mark and the prohibition field are located within the dicing groove;

[0025] The width of the forbidden region is greater than 40 μm and less than the width of the dicing groove.

[0026] like Figure 2 As shown, Figure 2 The diagram shows the structure of the marking for improving photolithographic overlay accuracy according to the present invention. In this embodiment, the marking for improving photolithographic overlay accuracy includes: an overlay mark 01; a forbidden region 02 surrounding the overlay mark 01; a scribe line 03; the overlay mark 01 and the forbidden region 02 located within the scribe line 03; the width b of the forbidden region 02 is greater than 40 μm and less than the width c of the scribe line 03.

[0027] Furthermore, in this embodiment, the outer shape of the overprint mark 01 is square.

[0028] Furthermore, in this embodiment, the outer shape of the forbidden domain 02 is a square, and the side length a of the square is 40 μm.

[0029] A method for improving photolithography overlay accuracy includes at least:

[0030] Step 1: Provide an overlay mark, the overlay mark having a prohibition zone around its periphery; the prohibition zone surrounds the overlay mark; the overlay mark and the prohibition zone are located within a dicing groove; the width of the prohibition zone is greater than 40 μm and less than the width of the dicing groove; for example... Figure 2 As shown, a forbidden area 02 is provided around the overlay mark 01; the forbidden area 02 surrounds the overlay mark 01; the overlay mark 01 and the forbidden area 02 are located in the dicing groove 03; the width of the forbidden area 02 is greater than 40μm and smaller than the width of the dicing groove 03.

[0031] Furthermore, in this embodiment, the outer shape of the overprint mark 01 in step one is square.

[0032] Furthermore, in this embodiment, the outer shape of the forbidden domain 02 in step one is a square, and the side length of the square is 40μm.

[0033] Step 2: Provide a substrate and deposit an epitaxial layer on the substrate;

[0034] Step 3: Use a photomask equipped with the overlay mark 01, the forbidden area 02 and the dicing groove 03 to measure the overlay accuracy of the epitaxial layer.

[0035] In summary, this invention improves the overlay accuracy of post-epitaxy photolithography by increasing the width of the forbidden region of the overlay mark. The deformation of the overlay mark after epitaxy is stable and controllable, and the overlay data is stable after multiple measurements. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0036] 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 marking for improving photolithographic registration accuracy, characterized in that, At least including: An overlay mark is provided; a forbidden zone is provided around the overlay mark; the forbidden zone surrounds the overlay mark; dicing groove; The overlay mark and the prohibited area are located within the dicing groove; The width of the forbidden region is greater than 40 μm and less than the width of the dicing groove.

2. The marking for improving photolithographic registration accuracy according to claim 1, characterized in that: The outer shape of the overprinted mark is square.

3. The marking for improving photolithographic registration accuracy according to claim 1, characterized in that: The outer shape of the forbidden region is a square, and the side length of the square is 40 μm.

4. The marking for improving photolithographic registration accuracy according to claim 1, characterized in that: The overlay marks are used to measure the overlay accuracy of the epitaxial layer.

5. A method for improving the accuracy of photolithography overlay, characterized in that, At least including: Step 1: Provide an overlay mark, the overlay mark having a prohibition zone around its periphery; the prohibition zone surrounds the overlay mark; the overlay mark and the prohibition zone are located within the dicing groove; the width of the prohibition zone is greater than 40 μm and less than the width of the dicing groove; Step 2: Provide a substrate and deposit an epitaxial layer on the substrate; Step 3: Use a photomask equipped with the overlay marks, forbidden regions, and dicing grooves to measure the overlay accuracy of the epitaxial layer.

6. The method for improving photolithography overlay accuracy according to claim 5, characterized in that: The outer shape of the overprinted mark in step one is square.

7. The method for improving photolithography overlay accuracy according to claim 5, characterized in that: The outer shape of the forbidden region in step one is a square, and the side length of the square is 40 μm.

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