ANTI-FUSE, METHOD FOR FABRICATING ANTI-FUSE, AND STORAGE APPARATUS THEREOF
20200051987 ยท 2020-02-13
Inventors
- Wenxuan Wang (Shenzhen, CN)
- Jian Shen (Shenzhen, CN)
- Hongchao Wang (Shenzhen, CN)
- Hongxing ZHOU (Shenzhen, CN)
Cpc classification
H01L23/5252
ELECTRICITY
H10B20/20
ELECTRICITY
International classification
H01L21/762
ELECTRICITY
Abstract
The present disclosure provides an anti-fuse, which includes at least one anti-fuse unit. The anti-fuse unit includes: a field-effect transistor, including a substrate, and a first doping region, a second doping region and a gate electrode that are disposed on the substrate; and a first electrode, arranged on the substrate and forming an anti-fuse capacitor with the substrate, the first electrode being connected to the first doping region, and configured to break down the anti-fuse capacitor by voltage adjustment between the second doping region and the substrate and write data to the anti-fuse unit, or configured to detect a current flowing through the second doping region by voltage adjustment for the gate electrode and determine whether to write data to the anti-fuse unit. By using the first electrode and the substrate as a pair of plates of the anti-fuse capacitor, a port of the anti-fuse unit may be omitted.
Claims
1. An anti-fuse, comprising at least one anti-fuse unit, the anti-fuse unit comprises: a field-effect transistor comprising a substrate, a first doped region, a second doped region and a gate electrode, wherein the first doped region, the second doped region, and the gate electrode are disposed on the substrate; and a first electrode arranged on the substrate and forming an anti-fuse capacitor with the substrate, wherein the first electrode is connected to the first doped region, and is configured to break down the anti-fuse capacitor by voltage adjustment between the second doped region and the substrate and write data to the anti-fuse unit, or is configured to detect a current flowing through the second doped region by voltage adjustment for the gate electrode and determine whether data is written to the anti-fuse unit.
2. The anti-fuse according to claim 1, wherein the anti-fuse unit further comprises a first insulation layer, the first insulation layer is disposed between the first electrode and the substrate.
3. The anti-fuse according to claim 2, wherein the anti-fuse unit further comprises a second insulation layer, the second insulation layer is disposed between the gate electrode and the substrate.
4. The anti-fuse according to claim 3, wherein the second insulation layer and the first insulation layer are formed simultaneously.
5. The anti-fuse according to claim 1, wherein the first electrode is a polysilicon plate, and/or the gate electrode is a polysilicon plate.
6. The anti-fuse according to claim 1, wherein the anti-fuse unit further comprises a first metal connection hole, the first doped region and the first electrode are connected by the first metal connection hole.
7. The anti-fuse according to claim 6, wherein the anti-fuse unit further comprises a second metal connection hole and a metal connection line layer, the second metal connection hole is configured to connect the second doped region to the metal connection line layer, or configured to connect the gate electrode to the metal connection line layer.
8. The anti-fuse according to claim 1, further comprising an isolation unit, the isolation unit is configured to isolate two adjacent anti-fuse capacitors from each other.
9. The anti-fuse according to claim 8, wherein the anti-fuse comprises a plurality of anti-fuse units arranged in rows and columns to form an anti-fuse array, two rows or two columns of adjacently disposed anti-fuse capacitors in the anti-fuse array sharing one isolation unit.
10. The anti-fuse according to claim 8, wherein the isolation unit is a shallow trench isolation unit or a third doped region.
11. The anti-fuse according to claim 10, wherein a contact position between the shallow trench isolation unit and the anti-fuse capacitor comprises an insulation portion; or the substrate is in contact with the third doped region, and the third doped region is provided with an external port such that the substrate is connected to the outside by the external port.
12. The anti-fuse according to claim 1, wherein the substrate is a P-type substrate, the first doped region and the second doped region are both N-type doped; or the substrate is an N-type substrate, the first doped region and the second doped region are both P-type doped.
13. The anti-fuse according to claim 1, wherein the substrate is connected to a fixed voltage.
14. A method for fabricating an anti-fuse, comprising: machining a substrate on a base by a front-end-of-line device machining process, and forming a first electrode, a first doped region, a gate electrode, and a second doped region on the substrate, wherein the first doped region, the second doped region, and the gate electrode form a field-effect transistor, and the first electrode and the substrate form the anti-fuse; and electrically connecting the first doped region to the first electrode by a back-end-of-line metal machining process.
15. The method according to claim 14, wherein the forming the first electrode and the gate electrode on the substrate comprises: forming the first electrode and the gate electrode on the substrate by an electrode machining process.
16. The method according to claim 15, wherein the forming the first electrode and the gate electrode on the substrate by the electrode machining process comprises: by a dual gate process, forming a first insulation layer and a second insulation layer simultaneously on the substrate, and forming the gate electrode and the first electrode simultaneously, the first electrode being disposed above the first insulation layer, and the gate electrode being disposed above the second insulation layer.
17. The method according to claim 14, further comprising: forming a shallow trench isolation unit by a shallow trench isolation process, the shallow trench isolation unit being configured to isolate the anti-fuse capacitor from an adjacent anti-fuse capacitor thereof.
18. The method according to claim 14, wherein the electrically connecting the first doped region to the first electrode by the back-end-of-line machining process comprises: forming a first metal connection hole by the back-end-of-line machining process to connect the first doped region to the first electrode by the first metal connection hole.
19. The method according to claim 14, further comprising: forming a second metal connection hole and a connection line layer by the back-end-of-line machining process, the second metal connection hole being configured to connect the second doped region to the metal connection line layer, or configured to connect the gate electrode to the metal connection line layer.
20. A storage apparatus, comprising a plurality of anti-fuse units arranged in rows and columns to form an anti-fuse array, wherein the anti-fuse unit comprises: a field-effect transistor comprising a substrate, a first doped region, a second doped region, and a gate electrode, wherein the first doped region, the second doped region, and the gate electrode are disposed on the substrate; and a first electrode arranged on the substrate and forming an anti-fuse capacitor with the substrate, wherein the first electrode is connected to the first doped region, and configured to break down the anti-fuse capacitor by voltage adjustment between the second doped region and the substrate and write data to the anti-fuse unit, or is configured to detect a current flowing through the second doped region by voltage adjustment for the gate electrode and determine whether data is written to the anti-fuse unit.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] For clearer description of the technical solutions in embodiments of the present disclosure or in the related art, hereinafter, drawings that are to be referred for description of the embodiments or the related art are briefly described. Apparently, the drawings described hereinafter merely illustrate some embodiments of the present disclosure. Persons of ordinary skill in the art may also derive other drawings based on the drawings described herein without any creative effort.
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
[0040] Reference numerals and denotations thereof:
[0041] 101base; 102substrate; 103first doped region; 104second doped region; 105gate electrode; 106first electrode; 107first insulation layer; 108second insulation layer; 109first metal connection hole; 110second metal connection hole; 111metal connection line layer; 112shallow trench isolation unit; 113insulation portion; 114field-effect transistor; 115anti-fuse capacitor; 116third doped region; 117external port; 21anti-fuse unit
DETAILED DESCRIPTION
[0042] Practice of the present disclosure is described in detail with reference to drawings and specific embodiments, such that the practice of addressing the technical problem using the technical means according to the present disclosure and achieving the technical effects may be better understood and conducted.
[0043]
[0044] In practice, the anti-fuse may include one or a plurality of anti-fuse units. For example, as illustrated in
[0045] Specifically, in this embodiment, the first doped region 103 is connected to the first electrode 106 (for example, the first doped region 103 is connected to the first electrode 106 by a first metal connection hole 109 as illustrated in
[0046] In the anti-fuse according to this embodiment, the first electrode 106 and the substrate 102 are respectively used as one of the plates of the anti-fuse capacitor 115, and thus one port of the anti-fuse capacitor 115 may be omitted (that is, the other plate of the anti-fuse capacitor described in the background). In this way, the size of the anti-fuse unit is reduced, and thus the size of the anti-fuse is reduced.
[0047] In addition, in this embodiment, the voltage difference between the second doped region 104 of the field-effect transistor 114 and the substrate 102 and the voltage of the gate electrode 105 are adjusted, such that data is written to the anti-fuse unit; or data in the anti-fuse unit is read, such that operations of the anti-fuse are simpler.
[0048] Exemplarily, in a specific application scenario, during writing data to one anti-fuse unit in the anti-fuse, a first voltage may be connected to the gate electrode 105 of the anti-fuse unit, such that a sufficient current channel is generated in the field-effect transistor while the field-effect transistor 114 is turned on, and hence a current which is sufficiently great to break down the anti-fuse capacitor 115 may flow through the field-effect transistor; and a second voltage may also be connected to the second doped region 104 of the anti-fuse unit, such that the voltage difference between the second doped region 104 and the substrate 102 is a predetermined breakdown voltage (in this process, the substrate 102 or a third doped region 116 hereinafter may be connected to the ground or at a 0 level).
[0049] On the premise that a current which is sufficiently great to break down the anti-fuse capacitor 115 may flow through the field-effect transistor, when the voltage difference between the second doped region 104 and the substrate 102 is the predetermined breakdown voltage, a voltage difference that may break down the anti-fuse capacitor 115 may be generated between the first electrode 106 and the substrate 102 to write data to the anti-fuse unit. For example, the current may flow through the first doped region 103 to the first electrode 106, and then break down the anti-fuse capacitor 115 to write data to the anti-fuse unit. Nevertheless, the current may also flow in a reverse direction. If the anti-fuse capacitor 115 is broken down, it indicates that the data written to the anti-fuse unit is 0, or the data written to the anti-fuse unit is 1, which is not limited in this embodiment.
[0050] In addition, since the first doped region 103 is connected to the first electrode 106 (for example, the first doped region 103 is connected to the first electrode 106 by the first metal connection hole 109 as illustrated in
[0051] In addition, in this embodiment, the substrate 102 may be connected to a fixed voltage (for example, a 0 V voltage) to ensure that a voltage of the plate of the anti-fuse capacitor is not abruptly changed, such that during writing data to the anti-fuse unit, the anti-fuse capacitor 115 is more easily broken down. Further, during reading data written to the anti-fuse unit, it is ensured that the current flowing through the second doped region 104 is stable.
[0052] This embodiment sets no limitation to the voltage value of the fixed voltage to which the substrate 102 is connected, the voltage value of the first voltage to which the gate electrode 105 is connected and the voltage value of the second voltage to which the second doped region 104 is connected, as long as it is ensured that the anti-fuse capacitor 115 may be broken down. For example, when the voltage value of the fixed voltage to which the substrate 102 is connected is low (for example, 0 V), for breakdown of the anti-fuse capacitor 115, under the circumstance where the first voltage ensures that the field-effect transistor 114 is turned on and provides sufficient current channels, the voltage value of the second voltage may be higher than the voltage value of the fixed voltage to which the substrate 102 is connected; or when the voltage value of the fixed voltage to which the substrate 102 is high (for example, 10 V), under the circumstance where the first voltage ensures that the field-effect transistor 114 is turned on and provides sufficient current channels, the voltage value of the second voltage may be lower than the voltage value of the fixed voltage to which the substrate 102 is connected. Referring to
[0053] (1) The substrate 102 is machined on the base 101 by a front-end-of-line device machining process, and the first electrode 106, the first doped region 103, the gate electrode 105 and the second doped region 104 are formed on the substrate 102. The first doped region, the second doped region and the gate electrode form a field-effect transistor, and the first electrode and the substrate form the anti-fuse.
[0054] Specifically, in this embodiment, the base 101 may be a wafer (for example, a silicon wafer) or a carrier for machining other semiconductor devices, which is not limited in this embodiment. Since the field-effect transistor 114 is an NMOS transistor, a doped region having a P-type device well is machined on the base 101. A dopant element may a P-type dopant element such as boron, such that the substrate 102 is a P-type substrate. Further, the first doped region 103, the second doped region 104 of the field-effect transistor 114 are machined on the P-type substrate. The first doped region 103 and the second doped region 104 are both N-type doped. A dopant element may be an N-type dopant element such as phosphorus.
[0055] In this embodiment, the first doped region 103 is a source of the NMOS transistor, and the second doped region 104 is a drain of the NMOS transistor. Nevertheless, in other implementations of the present disclosure, the first doped region 103 may be the drain of the NMOS transistor, and the second doped region 104 may be the source of the NMOS transistor, which are not limited in the present disclosure.
[0056] In this embodiment or other embodiments, a gate electrode 105 is further formed between the first doped region 103 and the second doped region 104. The gate electrode 105 may be specifically a polysilicon gate electrode. A gate oxide layer serving as a second insulation layer 108 may also be disposed between the gate electrode 105 and the substrate 102, to form an NMOS transistor, that is, the above described field-effect transistor 114.
[0057] In this embodiment, a first insulation layer 107 may also be disposed between the first electrode 106 and the substrate 102 to serve as a medium of the anti-fuse capacitor 115, and the first insulation layer 107 may be a gate oxide layer.
[0058] During machining, the first electrode and the gate electrode may be formed on the substrate by an electrode machining process.
[0059] Specifically, when the second insulation layer 108 and the first insulation layer 107 are made of the same material, and the first electrode 106 and the gate electrode 105 are made of different materials, by a MOS standard dual gate process, the second insulation layer 108 and the first insulation layer 107 may be simultaneously formed, and then the gate electrode 105 and the first electrode 106 are simultaneously formed. The first electrode is disposed above the first insulation layer, and the gate electrode is disposed above the second insulation layer, such that the anti-fuse according to the present disclosure may be obtained only by a machining process for machining a MOS transistor. In this way, additional processes such as finishing are not needed, thereby saving the cost.
[0060] Further, if the second insulation layer 108 and the first insulation layer 107 are both a gate oxide, a thickness of the first insulation layer 107 may be less than that of the second insulation layer 108. For example, the second insulation layer 108 is a thick gate oxide layer, and the first insulation layer 107 is a thin gate oxide layer. The terms thin and thick are merely relatively defined.
[0061] In this embodiment, the current for breaking down the anti-fuse capacitor 115 is provided by the field-effect transistor 114. If the anti-fuse capacitor 115 needs to be broken down, the field-effect transistor 114 needs to provide a sufficient current. A greater current signifies that the second doped region 104 of the field-effect transistor 114 needs to be connected to a greater voltage. Since the second insulation layer 108 is a thick gate oxide layer, it is thus ensured that the field-effect transistor 114 is not broken down while providing a current that is sufficient to break down the anti-fuse capacitor 115.
[0062] In addition, since the anti-fuse capacitor 115 needs to be broken down when data is to be written to the anti-fuse unit. When the first insulation layer 107 is a thin gate oxide layer, a smaller voltage or current may break down the anti-fuse capacitor 115, such that the anti-fuse capacitor 115 is easily broken down. In this way, the difficulty in writing data to the anti-fuse unit is low.
[0063] (2) The first electrode 106 is connected to the first doped region 103 by a back-end-of-line machining process on the basis of the front-end-of-line machining, and an externally connectable port such as a gate port and a drain port may be obtained by metal machining
[0064] In this embodiment, specifically, a metal connection hole (contact) is formed by the back-end-of-line metal machining process. The anti-fuse unit further includes the first metal connection hole 109. The first doped region 103 is connected to the first electrode 106 by the first metal connection hole 109.
[0065] In this embodiment, the process for forming the metal connection hole is briefly described hereinafter. The second metal connection hole and the shared connection hole hereinafter may be formed by the same back-end-of-line machining process with the first metal connection hole. Specifically, an insulation layer is added on the top of a semifinished product obtained by the front-end-of-line device machining process, etching is carried out at a predetermined position to obtain a through hole penetrating through the insulation layer and reaching the gate electrode, the first doped region and the second doped region, and a metal medium is filled in the through hole to obtain the metal connection hole.
[0066] By disposing the first metal connection hole 109, the first doped region 103 may be connected to the first electrode directly at the back-end-of-line metal machining stage. In this case, upon completion of the back-end-of-line metal machining stage, there is no need to additionally arrange an external connection, such that the structure of the anti-fuse unit is simpler and the machining is more convenient.
[0067] Further, as illustrated in
[0068] Nevertheless, in this embodiment, other metal connection holes may also be used, for example, the metal connection hole in a third embodiment hereinafter, as long as the metal connection hole may connect the first doped region 103 to the first electrode 106, which is not limited in this embodiment. Nevertheless, in this embodiment, the anti-fuse may further include a metal connection hole for another purpose.
[0069] In this embodiment, as illustrated in
[0070] Nevertheless, in this embodiment,
[0071] In addition, in this embodiment,
[0072] As illustrated in
[0073] For the purpose that the anti-fuse capacitor 115 disposed on the left side does not interfere with the anti-fuse capacitor 115 disposed on the right side in the two anti-fuse units in
[0074] In addition, if the anti-fuse array includes two rows or two columns of anti-fuse capacitors that are adjacently disposed, the two rows or two columns of anti-fuse capacitors that are adjacently disposed share one isolation unit.
[0075] Correspondingly, in the array layout of the anti-fuse in
[0076] Specifically, in this embodiment, the isolation unit illustrated in
[0077] In this embodiment, for the purpose that the anti-fuse capacitor 115 is more easily broken down, as illustrated in
[0078] In this embodiment, the insulation portion 113 may be specifically an oxidation recess (divot) formed at an intersection position between the shallow trench isolation unit 112 and the anti-fuse capacitor 115. Relative to the first insulation layer 107, a gate oxide layer at the oxidation recess (divot) is thinner, such that the difficulty in breaking down the anti-fuse capacitor 115 is lowered, and thus the difficulty in writing data to the anti-fuse unit is lowered. In addition, since the oxidation recess (divot) is a small-sized recess, the shape of the recess causes electric field distribution of the oxidation recess (divot) is more concentrated relative to other positions (for example, the first insulation layer 107), such that the gate oxide layer at the oxidation recess (divot) is more easily broken down likewise. In this way, the difficulty in breaking down the anti-fuse capacitor 115 is lowered, and the difficulty in writing data to the anti-fuse unit is lowered.
[0079] Nevertheless, in other implementations according to the present disclosure, the insulation unit may also be an oxide insulation layer. The oxide insulation layer may be practiced by a field oxide process. The isolation unit according to the present disclosure is not limited in this embodiment as long as the isolation unit may isolate two adjacently disposed anti-fuse capacitors.
[0080] Nevertheless,
[0081]
[0082] Specifically, in this embodiment, the doping type of the third doped region 116 may be the same as, or may be different from the doping type of the first doped region 103 or the second doped region 104, as long as two adjacently disposed anti-fuse capacitors 115 are isolated, and the anti-fuse capacitor 115 may be broken down. In addition, in this embodiment, since a doping concentration of the third doped region 116 is higher than that of the substrate, a current having a high magnitude may be provided by the third doped region 116. The current having a high magnitude causes the anti-fuse capacitor 15 to be more easily broken down.
[0083] In addition, in this embodiment, an external port 117 is disposed in the third doped region 116, such that the substrate 102 is connected to the outside by the external port 117, and thus the substrate 102 is electrically connected to an external circuit (for example, the control chip or the control circuit) of the anti-fuse. For example, the substrate 102 is connected to a fixed voltage by the external port 117.
[0084] Further, as illustrated in
[0085]
[0086] In this embodiment,
[0087]
[0088] An embodiment of the present disclosure further provides a storage apparatus. The storage apparatus includes the above described anti-fuse.
[0089] It should be noted that the above description of the number or quantity is merely intended to give clear interpretations for the embodiments of the present disclosure, rather than particular limitations.
[0090] In addition, a person skilled in the art should understand the above division of units and modules is only an exemplary one, and if the apparatus is divided into other units or modules or not divided, the technical solution shall also fall within the protection scope of the present disclosure as long as the information object has the above functions.
[0091] Although the preferred embodiments of the present disclosure are described above, once knowing the basic creative concept, a person skilled in the art can make other modifications and variations to these embodiments. Therefore, the appended claims are intended to be construed as covering the exemplary embodiments and all the modifications and variations falling within the scope of the present disclosure. Obviously, a person skilled in the art can make various modifications and variations to the present disclosure without departing from the spirit and scope of the present disclosure. In this way, the present disclosure is intended to cover the modifications and variations if they fall within the scope of the appended claims of the present disclosure and equivalent technologies thereof.