Low temperature drift ignition bridge structure and method of manufacturing same, semiconductor package structure

Abstract

The application provides a low-temperature drift integrated ignition bridge structure, a manufacturing method thereof and a semiconductor packaging structure. The low-temperature drift integrated ignition bridge structure comprises a substrate, a low-temperature drift thin film resistor and a protective film. In the application, the transverse size of the low-temperature drift thin film resistor at both ends is greater than the transverse size in the middle along the current flow direction, and the effective resistance area is the middle area. When designing, the resistance value can be effectively adjusted by adjusting the line width of the middle area, and the resistance value of the ignition bridge structure is convenient to control and adjust. Meanwhile, the protective film is arranged on the low-temperature drift thin film resistor, which can effectively prevent the surface of the low-temperature drift thin film resistor from being oxidized, improve the structural stability of the low-temperature drift thin film resistor and improve the ignition performance of the ignition bridge structure. The material of the low-temperature drift thin film resistor is a metal material with low-temperature drift coefficient such as chromium-silicon alloy, and the resistance temperature coefficient is relatively low, which guarantees the low-temperature drift characteristics of the ignition bridge structure resistance and is especially suitable for chip detonation in extreme environments such as low temperature and high temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology, and in particular to a low-temperature-drift integrated ignition bridge structure and a manufacturing method thereof, and a semiconductor packaging structure. BACKGROUND

[0002] In the field of semiconductor microelectronic devices, the long-term stability and reliability of electronic components are increasingly required, however, with the rapid development of modern information technology and the continuous evolution of hacking activities, information security problems have become increasingly important. In the field of modern commercial information security and resident privacy protection, storage media such as USB flash disks and mobile hard disks that store important user information will cause user information leakage or commercial secret leakage if lost or acquired by competitors, resulting in huge losses to user property and privacy.

[0003] Therefore, as a physical medium for information storage, electronic components are the physical carriers of information and technology, and need to be quickly destroyed in special environments or special occasions to prevent core sensitive information from being leaked. This requires the preparation of a safe chip that is fully compatible with existing semiconductor process technology, highly reliable, and can be quickly destroyed. However, in the prior art, the ignition bridge structure is generally used to achieve the non-recoverable breaking of the chip. However, the high reliability, low temperature drift requirements of the resistance in the ignition bridge structure in integrated circuits, especially in extreme environments, are increasingly high, requiring the resistance to have good stability, small temperature coefficient, simple process, and high process portability.

[0004] Therefore, there is an urgent need for a low-temperature-drift ignition bridge structure technology solution compatible with semiconductor processes. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a low-temperature-drift metal thin film integrated ignition bridge structure to be compatible with semiconductor processes and meet the requirements of low temperature drift and high reliability.

[0006] To achieve the above-mentioned objects and other related objects, the technical solutions provided by the present application are as follows.

[0007] A low-temperature-drift integrated ignition bridge structure, comprising:

[0008] a substrate unit;

[0009] a low-temperature-drift thin film resistance embedded in the substrate unit, the surface of which is flush with the surface of the substrate unit, and the transverse dimension of both ends is greater than that of the middle along the current flow direction;

[0010] a protective film arranged on the low-temperature-drift thin film resistance.

[0011] Optionally, the material of the low-temperature-drift thin film resistance comprises chromium-silicon alloy.

[0012] Optionally, the low-temperature drift thin-film resistor comprises a first electrode, a resistance wire and a second electrode connected in sequence, and the transverse size of the first electrode is greater than that of the resistance wire, and the transverse size of the second electrode is greater than that of the resistance wire along the flow direction of the current.

[0013] Optionally, the shape of the low-temperature drift thin-film resistor comprises a dog bone shape.

[0014] A manufacturing method of a low-temperature drift integrated ignition bridge structure, comprising:

[0015] providing a substrate comprising a plurality of substrate units arranged in an array;

[0016] performing a first etching to form grooves on the substrate units, and the grooves are independent of each other;

[0017] forming a resistance layer on the substrate, the resistance layer covers the substrate and fills each of the grooves, and the thickness of the resistance layer is equal to the depth of the grooves;

[0018] forming a protective layer on the resistance layer;

[0019] performing a second etching to remove the protective layer and the resistance layer except the grooves;

[0020] scribing and cutting the substrate to separate the plurality of substrate units, and each of the substrate units together with the resistance layer and the protective layer thereon constitutes an ignition bridge structure.

[0021] Optionally, the shape of the grooves comprises a dog bone shape, and the size of the two ends is greater than that of the middle.

[0022] Optionally, the material of the resistance layer comprises chromium-silicon alloy, and the material of the protective layer comprises inert metal.

[0023] Optionally, the mask of the first etching is complementary to the mask of the second etching.

[0024] A semiconductor packaging structure, comprising:

[0025] a plastic encapsulation body;

[0026] an energetic material arranged in the plastic encapsulation body;

[0027] the low-temperature drift integrated ignition bridge structure according to any one of the above is arranged in the plastic encapsulation body and located on the energetic material, and the protective film thereof is in contact with the energetic material;

[0028] a chip partially embedded in the plastic encapsulation body and located on the low-temperature drift integrated ignition bridge structure.

[0029] Optionally, in the low-temperature drift integrated ignition bridge structure, the low-temperature drift thin film resistor is electrically connected to an external trigger power source through lead posts at both ends of the low-temperature drift thin film resistor.

[0030] As described above, the low-temperature drift integrated ignition bridge structure and the manufacturing method thereof and the semiconductor package structure provided by the present application have at least the following beneficial effects:

[0031] Along the current flow direction, the transverse size at both ends of the low-temperature drift thin film resistor is greater than the transverse size in the middle, and the effective resistance area is the middle area. When designing, the resistance value can be effectively adjusted by adjusting the line width of the middle area, and the resistance value of the ignition bridge structure is relatively easy to control and adjust. At the same time, the protective film is arranged on the low-temperature drift thin film resistor, which can effectively prevent the surface of the low-temperature drift thin film resistor from being oxidized, improve the structural stability of the low-temperature drift thin film resistor, and improve the ignition performance of the ignition bridge structure. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figures 1-3 FIG. 1 is a structural schematic diagram of a low-temperature drift integrated ignition bridge structure in the present application.

[0033] Figures 4-12 FIG. 2 is a process flow diagram of a manufacturing method of a low-temperature drift integrated ignition bridge structure in the present application.

[0034] Figure 13 FIG. 3 is a resistance temperature drift curve diagram of a low-temperature drift integrated ignition bridge structure in an embodiment of the present application.

[0035] BRIEF DESCRIPTION OF DRAWINGS

[0036] 1 - substrate, 2 - resistance layer, 3 - protective layer, 10 - substrate unit, 20 - low-temperature drift thin film resistor, 30 - protective film, 201 - first electrode, 202 - resistance wire, 203 - second electrode. DETAILED DESCRIPTION

[0037] The embodiments of the present application will be described in detail below with specific reference to the drawings. Those skilled in the art can easily understand other advantages and effects of the present application from the disclosure of the present specification. The present application can also be implemented or applied by different specific embodiments, and the details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present application.

[0038] Please refer to Figures 1-13It is to be noted that the drawings provided in the embodiments only schematically illustrate the basic concepts of the present application, and thus only the components related to the present application are shown in the drawings, rather than being drawn according to the number, shape and size of the components in actual implementation, the type, number and proportion of each component in actual implementation can be arbitrarily changed, and the component layout type can also be more complex. The structure, proportion, size, etc. shown in the drawings attached to the present specification are only used to cooperate with the content disclosed in the specification, so as to be understood and read by those skilled in the art, and do not define the limiting conditions for the implementation of the present application, and therefore do not have technical substantive significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the present application, should still fall within the scope covered by the disclosed technology.

[0039] As described in the background section, the inventors found that the high reliability and low temperature drift requirements of the resistance in the ignition bridge structure are increasingly high in the research of the security chip, and the resistance is required to have good stability, small temperature coefficient, simple process and process compatibility, etc. However, the current ignition bridge technical solution cannot meet the above requirements.

[0040] Based on this, as shown in the drawings, Figures 1-3 The present application provides a low-temperature-drift integrated ignition bridge structure, which comprises:

[0041] a substrate unit 10;

[0042] a low-temperature-drift thin film resistance 20 embedded in the substrate unit 10, the surface of which is flush with the surface of the substrate unit 10, and the transverse dimension of the two ends is greater than that of the middle along the current flow direction;

[0043] a protective film 30 arranged on the low-temperature-drift thin film resistance 20.

[0044] In detail, as shown in the drawings, Figures 1-3 The substrate unit 10 mainly plays a bearing role, and can adopt commonly used silicon-based materials such as single crystal silicon.

[0045] In detail, in view of the special needs of modern information security protection, the low-temperature-drift thin film resistance 20 adopts a chromium-silicon alloy material with chromium and silicon as the main components. With the increase of the proportion of chromium material, the resistivity of the material decreases, and the temperature coefficient of resistance can gradually change from negative to positive. The sheet resistance is generally 0.5-5kΩ, and the temperature coefficient of resistance is (100-150)×10-6 / ℃. Therefore, the temperature drift of the resistance value of the low-temperature-drift thin film resistance 20 is very small and can be ignored, effectively improving the temperature stability and reliability of the ignition bridge structure.

[0046] In detail, as shown in the drawings, Figure 2As shown, the low-temperature drift thin-film resistor 20 includes a first electrode 201, a resistor wire 202 and a second electrode 203 connected in sequence, along the current flow direction (X-axis direction), the transverse dimension of the first electrode 201 (Y-axis direction) is greater than the transverse dimension of the resistor wire 202, and the transverse dimension of the second electrode 203 is greater than the transverse dimension of the resistor wire 202. Figure 2 Figure 2

[0047] Among them, the first electrode 201 and the second electrode 203 are electrically connected to both ends of the low-temperature drift thin-film resistor 20, which is convenient for subsequent electrical connection with the external trigger power supply, and the resistor wire 202 is the effective resistance area of the low-temperature drift thin-film resistor 20.

[0048] In detail, as shown in the drawings, Figure 2 The shape of the low-temperature drift thin-film resistor 20 includes a dog bone shape, or other shapes with thick ends and thin middle, such as an hourglass shape.

[0049] In detail, as shown in the drawings, Figure 1 Or Figure 3 As shown, a protective film 30 is provided on the low-temperature drift thin-film resistor 20, which is mainly to prevent the surface of the low-temperature drift thin-film resistor 20 from being oxidized to form an oxide layer, which will affect the electric fire efficiency of the ignition bridge. The material of the protective film 30 can be inert metals such as gold or platinum.

[0050] At the same time, as shown in the drawings, Figures 4-12 The application also provides a manufacturing method of the low-temperature drift integrated ignition bridge structure, which comprises the following steps:

[0051] S1, providing a substrate 1, the substrate 1 includes a plurality of substrate units 10 arranged in an array;

[0052] S2, performing first etching to form grooves T on the substrate units 10, and the plurality of grooves T are independent of each other;

[0053] S3, forming a resistance layer 2 on the substrate 1, the resistance layer 2 covers the substrate 1 and fills each groove T, and the thickness of the resistance layer 2 is equal to the depth of the groove T;

[0054] S4, forming a protective layer 3 on the resistance layer 2;

[0055] S5, performing second etching to remove the protective layer 3 and the resistance layer 2 outside the groove T;

[0056] S6, performing scribing and cutting processing on the substrate 1 to separate the plurality of substrate units 10, and each substrate unit 10 together with the resistance layer 20 and the protective layer 30 thereon constitutes an ignition bridge structure.

[0057] In detail, as shown in the drawings, Figure 4 The step S1 further comprises:​​

[0058] S11, select a substrate 1 with a front surface and a back surface arranged oppositely, and perform standard processes such as semiconductor wafer cleaning and marking on the substrate 1;

[0059] S12, determine the pattern and size of the ignition bridge structure, and divide the substrate 1 into a plurality of substrate units 10 arranged in an array from the front surface of the substrate 1.

[0060] In detail, as shown in Figures 4-6 S2 further includes:

[0061] S21, form a positive photoresist on the front surface of the substrate 1 and perform lithography to form a pattern structure of the ignition bridge structure;

[0062] S22, use the positive photoresist after lithography as a mask to etch each substrate unit 10 on the substrate 1, transfer the pattern structure of the ignition bridge structure to the substrate 1, and form a groove T on each substrate unit 10, and the grooves T are independent of each other.

[0063] The shape of the groove T includes a dog bone shape, the size of the two ends is larger than the middle, or the shape of the groove T can also be other shapes such as a sandglass shape.

[0064] In detail, as shown in Figure 7 S3 further includes:

[0065] S31, remove the positive photoresist remaining on the substrate 1;

[0066] S32, form a resistance layer 2 on the front surface of the substrate 1 by sputtering, electron beam evaporation or vacuum evaporation, etc., the resistance layer 2 covers the substrate 1 and fills each groove T, and the thickness of the resistance layer 2 is equal to the depth of the groove T, so as to ensure that the surface of the resistance layer 2 after deposition in the groove T is flush with the front surface of the substrate 1.

[0067] The thickness of the resistance layer 2 ranges from 100 angstroms to 2000 angstroms, and the material of the resistance layer 2 is chromium-silicon alloy, which has a relatively low resistance temperature coefficient to ensure the low temperature drift characteristics of the resistance formed subsequently.

[0068] In detail, as shown in Figure 8 S4 includes forming a protective layer 3 on the resistance layer 2 by sputtering, electron beam evaporation or vacuum evaporation, etc., and the protective layer 3 covers the resistance layer 2.

[0069] The thickness of the protective layer 3 is 10-50 angstroms, and the material of the protective layer 3 is inert metal, such as gold or platinum gold. The protective layer 3 is mainly used to prevent the natural oxidation layer from being formed on the surface of the resistance layer 2, so as to affect the resistance and ignition performance of the ignition bridge structure.

[0070] In detail, as shown in Figures 9-10 The step S5 of performing the second etching further includes:

[0071] S51, forming a negative photoresist on the protective layer 3 and performing photoetching to form a complementary structure of the ignition bridge structure pattern structure;

[0072] S52, using the photoetched negative photoresist as a mask to etch the protective layer 3 and the resistance layer 2 on the substrate 1, and removing the protective layer 3 and the resistance layer 2 except the groove T.

[0073] The mask for the first etching is complementary to the mask for the second etching, that is, the structure of the second photoetching is exactly complementary to the structure of the first photoetching. The etching area formed by the first positive photoresist is consistent with the protection area formed by the second negative photoresist, so as to ensure that the surface of the resistance layer 2 after deposition in the groove T is flush with the front surface of the substrate 10. At the same time, the second photoetching needs to be accurately positioned with the first photoetching to ensure that the two photoetching patterns are accurately complementary.

[0074] In detail, as shown in Figures 11-12 The step S6 of performing the dicing and cutting processing includes: performing the dicing and cutting processing on the substrate 1 along the cutting path planned in the step S1 to separate the plurality of substrate units 10. Each substrate unit 10, together with a part of the resistance layer 2 and a part of the protective layer 3, forms a low-temperature-drift thin-film resistance 20 and a protective film 30, which together constitute an ignition bridge structure.

[0075] It should be noted that, before the dicing and cutting, the ignition bridge structure on each substrate unit 10 needs to be electrically tested to verify whether the resistance value, temperature coefficient and uniformity meet the design requirements. Before the dicing and cutting, the back surface of the substrate 1 needs to be planarized and thinned. After the dicing and cutting, the plurality of ignition bridge structures need to be sorted.

[0076] Finally, as shown in Figure 1 or as shown in Figure 12The low-temperature drift integrated ignition bridge structure shown includes a substrate 10, a low-temperature drift thin film resistor 20 and a protective film 30, and the main body is in the shape of a dog bone; the line width of the central region of the low-temperature drift integrated ignition bridge structure can be properly adjusted according to actual ignition needs, and is generally 0.1-10 microns, because the ignition bridge structure triggers the chain reaction of the energetic material by generating heat through Joule heat, and the Joule heat E=I2 / R, wherein E is the energy released by the ignition bridge, in joules, I is the current passing through the ignition bridge structure, in amperes, and R is the resistance of the ignition bridge structure, in ohms, and the size of the resistance R is inversely proportional to the line width of the ignition bridge structure.

[0077] In an optional embodiment of the present application, as shown in Figure 13 as shown in Figure 1 or as shown in Figure 12 The resistance-temperature drift curve of the low-temperature drift integrated ignition bridge structure 100 square resistors is measured, and Figure 13 it can be known that the temperature drift coefficient is very low, the first-order temperature coefficient TCR1=33.25×10-6 PPM / ℃, and the second-order temperature coefficient TCR2=1.097×10-7 PPM / ℃, that is, the resistance-temperature coefficient of the ignition bridge structure is as low as 33.25×10-6 PPM / ℃, and the resistance value is relatively stable whether in a low-temperature environment of-55℃ or in a high-temperature environment of 125℃, and the temperature drift of the resistance value is not more than 1%.

[0078] In addition, based on the above low-temperature drift integrated ignition bridge structure, the present application also provides a semiconductor packaging structure, which includes:

[0079] a plastic package body;

[0080] an energetic material arranged in the plastic package body;

[0081] The above low-temperature drift integrated ignition bridge structure is arranged in the plastic package body and located on the energetic material, and the protective film thereof is in contact with the energetic material;

[0082] a chip partially embedded in the plastic package body and located on the low-temperature drift integrated ignition bridge structure.

[0083] In the low-temperature drift integrated ignition bridge structure, the two ends of the low-temperature drift thin film resistor are electrically connected to an external trigger power source through lead pillars.

[0084] In summary, in the low-temperature drift integrated ignition bridge structure, the manufacturing method thereof, and the semiconductor packaging structure, along the current flow direction, the transverse size of the low-temperature drift thin film resistor at two ends is greater than the transverse size in the middle, the effective resistance area is the middle area, and the resistance value can be effectively adjusted by adjusting the line width of the middle area in the design, so that the resistance value of the ignition bridge structure is convenient to control and adjust. At the same time, the protective film is arranged on the low-temperature drift thin film resistor, which can effectively prevent the surface of the low-temperature drift thin film resistor from being oxidized, improve the structural stability of the low-temperature drift thin film resistor, and improve the ignition performance of the ignition bridge structure. The material of the low-temperature drift thin film resistor is a metal material with low-temperature drift coefficient such as chromium-silicon alloy, and the resistance temperature coefficient is relatively low, which guarantees the low-temperature drift characteristics of the ignition bridge structure resistance, and is especially suitable for chip detonation in extreme environments such as low temperature and high temperature. The overall process of the manufacturing method is simple, stable, and compatible with the existing semiconductor process. The integrated ignition bridge structure and other areas of the substrate are at the same level, easy to package and integrate, and do not increase the complexity of packaging. In the semiconductor packaging structure after packaging, the ignition bridge structure is in close contact with the target chip and the energetic material, which is convenient for realizing stable and reliable electrical detonation, realizing the non-recoverable burst of the safety chip, guaranteeing the safety of the chip sensitive information, and preventing information from being stolen.

[0085] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A low-temperature drift integrated ignition bridge structure, characterized in that, include: Basis unit; A low-temperature drift thin-film resistor is embedded in the substrate unit, with its surface flush with the surface of the substrate unit, and its lateral dimensions at both ends are larger than those in the middle along the direction of current flow. A protective film is disposed on the low-temperature drift thin-film resistor and completely covers the low-temperature drift thin-film resistor; The low-temperature drift thin-film resistor includes a first electrode, a resistance wire, and a second electrode connected in series. Along the direction of current flow, the lateral dimension of the first electrode is larger than the lateral dimension of the resistance wire, and the lateral dimension of the second electrode is larger than the lateral dimension of the resistance wire.

2. The low-temperature drift integrated ignition bridge structure according to claim 1, characterized in that, The material of the low-temperature drift thin-film resistor includes a chromium-silicon alloy.

3. The low-temperature drift integrated ignition bridge structure according to claim 1, characterized in that, The shape of the cryogenic drift thin-film resistor includes a dog bone shape.

4. A method for manufacturing a low-temperature drift integrated ignition bridge structure, characterized in that, include: A substrate is provided, the substrate comprising a plurality of substrate units arranged in an array; The first etching is performed to form grooves on the substrate unit, and the multiple grooves are independent of each other; A low-temperature drift thin film resistive layer is formed on the substrate, the low-temperature drift thin film resistive layer covers the substrate and fills each of the grooves, and the thickness of the low-temperature drift thin film resistive layer is equal to the depth of the grooves; A protective layer is formed on the low-temperature drift thin film resistive layer; A second etching process is performed to remove the protective layer and the low-temperature drift thin film resistive layer outside the groove; The substrate is diced to separate multiple substrate units, and each substrate unit, together with its resistive layer and protective layer, forms an ignition bridge structure.

5. The method for manufacturing a low-temperature drift integrated ignition bridge structure according to claim 4, characterized in that, The groove has a shape resembling a dog bone, with the dimensions at both ends being larger than the dimensions in the middle.

6. The method for manufacturing a low-temperature drift integrated ignition bridge structure according to claim 5, characterized in that, The material of the low-temperature drift thin film resistive layer includes a chromium-silicon alloy, and the material of the protective layer includes an inert metal.

7. The method for manufacturing a low-temperature drift integrated ignition bridge structure according to claim 6, characterized in that, The mask used in the first etching is complementary to the mask used in the second etching.

8. A semiconductor packaging structure, characterized in that, include: Plastic encapsulation; Energetic material is disposed within the encapsulation body; The low-temperature drift integrated ignition bridge structure according to any one of claims 1-3 is disposed within the plastic encapsulation body and located on the energetic material, and its protective film is in contact with the energetic material; The chip is partially embedded in the plastic package and located on the low-temperature drift integrated ignition bridge structure.

9. The semiconductor packaging structure according to claim 8, characterized in that, In the aforementioned cryogenic drift integrated ignition bridge structure, the two ends of the cryogenic drift thin film resistor are electrically connected to an external trigger power supply via lead posts.

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