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KR-20260065545-A - Method of Wafer-to-Wafer Hybrid Bonding and Method of Die-to-Wafer Hybrid Bonding

KR20260065545AKR 20260065545 AKR20260065545 AKR 20260065545AKR-20260065545-A

Abstract

The present invention relates to a wafer-to-wafer hybrid bonding method and a die-to-wafer hybrid bonding method, and more specifically, to a wafer-to-wafer hybrid bonding method and a die-to-wafer hybrid bonding method for bonding wafers to each other or bonding a die having a semiconductor circuit formed thereon to a wafer. The wafer-to-wafer hybrid bonding method and the die-to-wafer hybrid bonding method of the present invention have the advantage of improving the productivity of the semiconductor device manufacturing process and reducing manufacturing costs by shortening the time required for the hybrid bonding process when bonding wafers to wafers or bonding a wafer to a die.

Inventors

  • 고윤성

Assignees

  • 주식회사 프로텍

Dates

Publication Date
20260508
Application Date
20251029
Priority Date
20241029

Claims (12)

  1. A wafer-to-wafer hybrid bonding method for bonding a first wafer and a second wafer having a structure in which a metal pattern is formed on a dielectric layer, wherein (a) A step of placing the first wafer on a base; (b) a step of aligning the second wafer with respect to the first wafer so that the metal pattern portions of the first wafer and the second wafer correspond to each other, and placing the second wafer on the upper surface of the first wafer to provide a wafer assembly; and (c) a step of bonding the dielectric layers of the first wafer and the second wafer to each other and bonding the metal patterns to each other by irradiating the wafer assembly with a laser to heat the wafer assembly; a wafer-to-wafer hybrid bonding method comprising.
  2. In paragraph 1, (d) a step of pressing the second wafer against the first wafer while performing the above step (c); further comprising a wafer-to-wafer hybrid bonding method.
  3. In paragraph 2, The above step (d) involves pressing the second wafer using a pressurizing member made of a transparent material capable of transmitting laser light, and The above step (c) is a wafer-to-wafer hybrid bonding method performed by irradiating a laser onto the wafer assembly through the pressure member.
  4. In any one of paragraphs 1 through 3, (e) a step of surface-activating the first wafer and the second wafer by plasma treatment before performing the above step (a); further comprising, The above step (b) is a wafer-to-wafer hybrid bonding method in which the dielectric layer portions of the first wafer and the second wafer, surface-activated by the above step (e), are hydrogen-bonded to each other to form the wafer assembly.
  5. In paragraph 4, A wafer-to-wafer hybrid bonding method in which, by step (c) above, the dielectric layer portions of the first wafer and the second wafer are bonded in the form of a covalent bond by a dehydration condensation reaction, and the metal pattern portions of the first wafer and the second wafer are bonded to each other by metal diffusion.
  6. A die-to-wafer hybrid bonding method in which a plurality of dies having a structure in which a metal pattern is formed on a dielectric layer are each bonded to a wafer having a structure in which a metal pattern is formed on a dielectric layer, (a) A step of placing the wafer on a base; (b) a step of aligning the plurality of dies with respect to the wafer such that the metal pattern portions of the wafer and the plurality of dies correspond to each other, and arranging the plurality of dies on the upper surface of the wafer to form a wafer-die assembly; and (c) a step of bonding the wafer and a plurality of dies to each other by heating the wafer-die assembly by irradiating the wafer-die assembly with a laser; a hybrid bonding method of die to wafer.
  7. In paragraph 6, (d) a step of applying pressure to each of the plurality of dies against the wafer while performing the above step (c); further comprising a hybrid bonding method of die to wafer.
  8. In Paragraph 7, Step (d) above involves applying pressure to each of the plurality of dies using a pressure member made of a transparent material capable of transmitting laser light, and The above step (c) is a hybrid bonding method of die to wafer performed by irradiating a laser onto the wafer assembly through the pressure member.
  9. In paragraph 8, The above step (d) is performed by simultaneously pressing a plurality of dies with the pressurizing member, and The above step (c) is a hybrid bonding method of die to wafer, performed by simultaneously irradiating a laser on a plurality of dies pressed by the pressurizing member.
  10. In paragraph 8, The above step (d) is performed by sequentially pressing a plurality of dies with the pressing member, and The above step (c) is a hybrid bonding method between a die and a wafer, performed by irradiating a laser onto each of a plurality of dies that are sequentially pressed by the above step (d).
  11. In any one of paragraphs 6 through 10, (e) a step of surface-activating the wafer and die by plasma treatment before performing the above step (a); further comprising, The above step (b) is a hybrid bonding method of die to wafer in which the dielectric layer portions of the wafer and the plurality of dies surface-activated by the above step (e) are hydrogen-bonded to each other to form the wafer-die assembly.
  12. In Paragraph 11, A hybrid bonding method between a die and a wafer in which, by step (c) above, the dielectric layer portions of the wafer and the die are bonded in the form of covalent bonds by a dehydration condensation reaction, and the metal pattern portions of the wafer and the die are bonded to each other by metal diffusion.

Description

Method of Wafer-to-Wafer Hybrid Bonding and Method of Die-to-Wafer Hybrid Bonding The present invention relates to a wafer-to-wafer hybrid bonding method and a die-to-wafer hybrid bonding method, and more specifically, to a wafer-to-wafer hybrid bonding method and a die-to-wafer hybrid bonding method for bonding wafers to each other or bonding a die having a semiconductor circuit formed thereon to a wafer. Conventionally, a bonding method using solder balls was widely used to mount semiconductor chips on a substrate. Such solder balls typically have a diameter of about 100 µm. Therefore, when producing semiconductor devices using semiconductor chips with a pitch of within a few µm, it is difficult to use solder balls, and other means of electrode connection are required. A hybrid bonding method is used to produce semiconductor chips with electrode pitch spacing of within a few micrometers. After forming a metal electrode pattern on the dielectric layer of a wafer or die through a semiconductor process, a method is used to bond wafers to wafers or wafers to die. In this case, the process in which the dielectric layer portions between the wafers or dies being bonded are bonded to each other and the metal electrode portions are bonded to each other is called hybrid bonding. At this time, after temporarily bonding the wafers to each other or the wafers to the die using methods such as hydrogen bonding, an annealing process is performed. When the wafers are inserted into a high-temperature chamber and an annealing process is performed for about 1 to 2 hours, the dielectric layer portions are bonded to each other and the metal electrode portions are bonded to each other. In this way, it is possible to manufacture ultra-small, highly integrated semiconductor devices by bonding microelectrodes to each other without using connecting means such as solder balls. However, as mentioned above, performing annealing for such hybrid bonding takes about 1 to 2 hours, which leads to a problem of reduced productivity in the overall hybrid bonding process. Therefore, if the time required to perform hybrid bonding can be shortened, it is possible to improve the productivity of the overall semiconductor device manufacturing process and reduce manufacturing costs. FIG. 1 is a cross-sectional view illustrating the process of carrying out a wafer-to-wafer hybrid bonding method according to one embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating the process of implementing a hybrid bonding method between a die and a wafer according to one embodiment of the present invention. Hereinafter, a hybrid bonding method between wafers according to an embodiment of the present invention will be described with reference to the attached drawings. FIG. 1 is a diagram illustrating the process of carrying out a wafer-to-wafer hybrid bonding method according to one embodiment of the present invention. In this embodiment, the first wafer (100) and the second wafer (200) bonded to each other are each formed with a structure in which a device and a circuit are formed by a semiconductor process on a dielectric layer such as silicon, and a pattern is formed by a metal such as copper for electrical connection. The first wafer (100) and the second wafer (200) are configured such that electrode patterns are formed at corresponding positions so that a 3D integrated circuit can be manufactured by stacking and bonding them together. The present invention is intended to bond the first wafer (100) and the second wafer (200) together. In order to bond the first wafer (100) and the second wafer (200) to each other, the first wafer (100) and the second wafer (200) have their surfaces uniformly flattened by a Chemical Mechanical Planarization (CMP) process. The surfaces of the metal pattern (130, 230) portions of the first wafer (100) and the second wafer (200) may also be finely concave by the CMP process. Thus, the first wafer (100) and the second wafer (200), having completed the CMP process, undergo a surface activation process by plasma treatment (step (e)). Through such plasma treatment, the first wafer (100) and the second wafer (200) become hydrated. In this state, the dielectric layer (110, 210) portion of the first wafer (100) and the second wafer (200) is made hydrated by means such as passing through a chamber containing water vapor. In this state, the first wafer (100) is placed on a horizontal table-shaped base (400) (step (a)). Next, a wafer assembly (WW) is prepared by aligning the second wafer (200) with respect to the first wafer (100) so that the metal pattern portions (130, 230) of the first wafer (100) and the second wafer (200) correspond to each other, and placing the second wafer (200) on the upper surface of the first wafer (100) (step (b)). By bringing the surfaces of the dielectric layer portions (110, 210) of the first wafer (100) and the second wafer (200) into contact with each other through this process,