Interlayer gap filling device and method
By combining a gap detection module, a nozzle array, and a UV LED array, selective filling of interlayer gaps is achieved, solving the problems of material waste and incomplete filling in existing technologies, improving filling quality and material utilization, and simplifying the process.
Patent Information
- Application Number
- CN202511728330.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-27
AI Technical Summary
Existing interlayer gap filling methods suffer from problems such as high material waste, incomplete filling of depth-to-width ratio gaps, high void ratio, and complex processes. In particular, it is difficult to achieve efficient and selective filling in gaps with high depth-to-width ratios and heterogeneous integrated structures.
By employing a gap detection module, a nozzle array, and an ultraviolet LED array combined with an adaptive motion control system, selective filling of interlayer gaps is achieved. Organic resin is sprayed and cured under ultraviolet light, and the position is corrected in real time by an infrared sensor. Nano-silica and carbon nanotubes are used to reinforce the filling material.
It improves material utilization, reduces the amount of organic resin used, enhances aspect ratio and filling quality, reduces void ratio, simplifies process flow, supports flexible substrates and heterogeneous integration, and avoids additional photolithography or etching steps.
Smart Images
Figure CN121586352A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor integrated circuit manufacturing, and particularly to an interlayer gap filling apparatus. This invention also relates to an interlayer gap filling method. Background Technology
[0002] After die bonding, interlayer gaps are formed, which need to be filled with insulating material. For example... Figure 1 The diagram shows a schematic of the interlayer gap structure after bonding existing chips. Semiconductor devices are formed in wafer 102a of the semiconductor substrate. A back-end process layer (BEOL) 103a, i.e., a metal interconnect structure, is formed on the front side of wafer 102a, and a metal redistribution layer (RDL) 104a is formed on the back side of wafer 102a. The front side of the BEOL layer 103a is bonded to a carrier wafer 101. Semiconductor devices are formed in wafer 102b of the semiconductor substrate. A BEOL layer 103b is formed on the front side of wafer 102b, and a metal redistribution layer 104b is formed on the front side of the BEOL layer 103b. The metal redistribution layers 104a and 104b are bonded together by hybrid bonding (HB) pads. It can be seen that wafer 102b includes multiple chips. Figure 1 The image shows chips 106a and 106b, with an interlayer gap 107 between them.
[0003] The first existing method for filling interlayer gaps involves coating an entire sheet of insulating material, such as... Figure 2 The diagram shown is a schematic representation of the structure after coating with insulating material using the first existing interlayer gap filling method; it includes the following steps: spin-coating or scraping epoxy resin, polyimide, silica sol, and other materials 202 onto the surface of the stacked wafer 201. The wafer 201 has the following characteristics: Figure 1 The diagram shows a stacked structure of three wafers. The shortcomings of the existing first-generation interlayer gap-filling method include:
[0004] Material waste rate is as high as 70% (non-seam areas are covered);
[0005] Gaps with a depth-to-width ratio greater than 5:1 are not completely filled, with a void rate greater than 10%.
[0006] Subsequent photolithography or etching is required to remove excess resin, making the process highly complex.
[0007] The second existing method for filling interlayer gaps involves filling them by depositing oxides, including the steps of depositing inorganic materials such as SiO2 by CVD / PECVD.
[0008] The drawbacks of the existing second method for filling interlayer gaps include:
[0009] The deposition rate is slow; for example, when the fissure depth is >30μm, the deposition time is >2 hours.
[0010] High stress, such as >500MPa, can lead to the risk of interface delamination.
[0011] The surface exhibits significant thickness variations after deposition, necessitating an additional planarization process. Summary of the Invention
[0012] The technical problem to be solved by the present invention is to provide an interlayer gap filling device that can selectively fill interlayer gaps, thereby avoiding the filling of organic resin outside the interlayer gaps and thus improving material utilization and reducing the amount of organic resin used; it can also improve the filling quality, increase the depth-to-width ratio that can be filled and reduce the filling void rate; and it can also simplify the filling process. To this end, the present invention also provides an interlayer gap filling method.
[0013] To solve the above-mentioned technical problems, the interlayer gap filling device provided by the present invention includes:
[0014] The gap detection module is used to detect and locate gaps between layers.
[0015] An array of nozzles, consisting of multiple nozzles, is used to spray organic resin to fill the interlayer gaps.
[0016] An ultraviolet LED array is used to cure the organic resin under ultraviolet light.
[0017] The motion mechanism, the nozzle array, the gap detection module and the ultraviolet LED array are all mounted on the motion mechanism.
[0018] An adaptive motion control system is used to control the movement of the motion mechanism and drive the nozzle array, the gap detection module and the ultraviolet LED array to move. Based on the three-dimensional coordinates of the real-time positioning of the interlayer gap obtained by the gap detection module, the motion mechanism is controlled to drive the nozzle array to move along the path of the interlayer gap to achieve selective filling of the interlayer gap.
[0019] A further improvement is that the interlayer gap is the gap after chip bonding.
[0020] A further improvement is that the gap detection module uses an optical microscope or laser scanning equipment to obtain the three-dimensional coordinates of the interlayer gap.
[0021] A further improvement is that the ultraviolet LED array and the nozzle array move synchronously to achieve synchronous ultraviolet curing of the filled organic resin.
[0022] A further improvement is that the nozzle aperture of the nozzle array is 10 micrometers to 50 micrometers, and the nozzle sprays the organic resin in a pulse mode.
[0023] The volume of the organic resin droplets sprayed by the nozzle is 0.1 pL to 10 pL, the spraying pressure is 10 kPa to 50 kPa, and the frequency is 1 kHz to 10 kHz.
[0024] A further improvement is that the organic resin comprises 5 wt% to 15 wt% of nano-silica and 1 wt% to 5 wt% of carbon nanotubes.
[0025] A further improvement is that the motion mechanism includes a six-axis robotic arm, which drives the spraying path along the interlayer gap of the nozzle array, and the positioning accuracy of the spraying path is ±0.5 micrometers.
[0026] A further improvement is that the nozzle is also integrated with an infrared sensor to correct the position of the interlayer gap in real time.
[0027] To solve the above-mentioned technical problems, the interlayer gap filling method provided by the present invention includes the following steps:
[0028] A gap detection module is used to detect and locate gaps between layers.
[0029] Organic resin is sprayed to fill the interlayer gaps using a nozzle array consisting of multiple nozzles.
[0030] The filling material is cured using an ultraviolet LED array.
[0031] The nozzle array, the gap detection module, and the ultraviolet LED array are all mounted on the motion mechanism. An adaptive motion control system controls the motion mechanism to move and drive the nozzle array, the gap detection module, and the ultraviolet LED array. Based on the real-time three-dimensional coordinates of the interlayer gap obtained by the gap detection module, the motion mechanism is controlled to move the nozzle array along the path of the interlayer gap to achieve selective filling of the interlayer gap.
[0032] A further improvement is that the interlayer gap is the gap after chip bonding.
[0033] A further improvement is that the gap detection module uses an optical microscope or laser scanning equipment to obtain the three-dimensional coordinates of the interlayer gap.
[0034] A further improvement is that the ultraviolet LED array and the nozzle array move synchronously to achieve synchronous ultraviolet curing of the filled organic resin.
[0035] A further improvement is that the nozzle aperture of the nozzle array is 10 micrometers to 50 micrometers, and the nozzle sprays the filling material in a pulse mode.
[0036] The volume of the droplets of the filler material sprayed by the nozzle is 0.1 pL to 10 pL, the spraying pressure is 10 kPa to 50 kPa, and the frequency is 1 kHz to 10 kHz.
[0037] A further improvement is that the organic resin comprises 5 wt% to 15 wt% of nano-silica and 1 wt% to 5 wt% of carbon nanotubes.
[0038] A further improvement is that the motion mechanism includes a six-axis robotic arm, which drives the spraying path along the interlayer gap of the nozzle array, and the positioning accuracy of the spraying path is ±0.5 micrometers.
[0039] A further improvement is that the nozzle is also integrated with an infrared sensor to correct the position of the interlayer gap in real time.
[0040] A further improvement is that, after all the interlayer gaps have been filled, the process further includes:
[0041] The organic resin is then heat-cured by baking.
[0042] This invention combines a gap detection module for detecting and locating interlayer gaps with an adaptive motion control system for controlling the movement of the motion mechanism. This allows organic resin to fill only the interlayer gaps, thus enabling selective filling of the gaps. This avoids organic resin filling outside the gaps, thereby improving material utilization and reducing the amount of organic resin used. For example, compared to existing methods, the amount of organic resin used in this invention can be reduced by 80%.
[0043] This invention employs a nozzle array composed of multiple nozzles to spray organic resin. The nozzle orifice diameter can be set to a smaller value. Combined with the setting of the spraying mode, such as pulse spraying, it can improve the filling quality, increase the aspect ratio that can be filled, and reduce the filling void rate. For example, the maximum aspect ratio that can achieve good filling can reach 20:1, while the aspect ratio supported by existing methods is less than 5:1. The void rate after filling by this invention is less than 0.5%, while the void rate of existing methods is greater than 10%.
[0044] Since the present invention does not fill the gaps between layers with organic resin, there is no need to add additional photolithography or etching to remove excess organic resin, thus simplifying the filling process.
[0045] The present invention also features strong compatibility, including: support for flexible substrates (such as PI thin films) and heterogeneous integration (silicon + glass); and adaptability to TSV exposed structures, avoiding the covering of conductive channels by chip (die) filling materials. Attached Figure Description
[0046] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:
[0047] Figure 1 This is a schematic diagram of the interlayer gap structure after existing chip bonding;
[0048] Figure 2 This is a schematic diagram of the structure after applying insulating material using the first existing interlayer gap filling method;
[0049] Figure 3 This is a schematic diagram of the interlayer gap filling device according to an embodiment of the present invention;
[0050] Figure 4A This is a schematic diagram of the interlayer gap filling device of the present invention detecting and locating interlayer gaps;
[0051] Figure 4B This is a schematic diagram of the interlayer gap filling device of the present invention filling the interlayer gap with sprayed organic resin.
[0052] Figure 4C This is a schematic diagram of the interlayer gap filling device of the present invention undergoing ultraviolet curing.
[0053] Figure 5A This is a schematic diagram of the structure of the interlayer gap corresponding to the interlayer gap filling device in an embodiment of the present invention;
[0054] Figure 5B This is a schematic diagram of the structure of the interlayer gap filling device after filling the interlayer gap in an embodiment of the present invention. Detailed Implementation
[0055] like Figure 3 The diagram shown is a structural schematic of the interlayer gap filling device according to an embodiment of the present invention; as shown Figure 4A The diagram shown is a schematic representation of the interlayer gap filling device detecting and locating the interlayer gap 402 according to an embodiment of the present invention; as shown... Figure 4B The diagram shown is a schematic diagram of the interlayer gap filling device of the present invention filling interlayer gap 402 with sprayed organic resin 403; as shown Figure 4C The diagram shown is a schematic diagram of the interlayer gap filling device of the present invention undergoing ultraviolet curing; the interlayer gap filling device of the present invention includes:
[0056] The gap detection module 301 is used to detect and locate interlayer gaps 402. For example... Figure 4AThe diagram shown is a schematic diagram of the gap detection module 301 detecting and locating the interlayer gap 402.
[0057] In this invention, the gap detection module 301 uses an optical microscope or laser scanning device to obtain the three-dimensional coordinates of the interlayer gap 402.
[0058] like Figure 4A As shown, the interlayer gap 402 is the gap after chip bonding, and the interlayer gap 402 is located on the wafer 401 after chip bonding.
[0059] like Figure 5A The diagram shown is a structural schematic of the interlayer gap corresponding to the interlayer gap filling device in an embodiment of the present invention. Figure 5A This is a cross-sectional structural diagram corresponding to the wafer 401. The wafer 401 can employ... Figure 1 The wafer formed by bonding the carrier wafers 101, 102a, and 102b shown is illustrated in the figure. Please refer to the specific structure for details. Figure 1 As shown.
[0060] An array of nozzles 302 is used to spray organic resin 403 to fill the interlayer gaps 402. For example... Figure 4B The diagram shown is a schematic of the nozzle array spraying organic resin 403 to fill the interlayer gaps 402.
[0061] In this embodiment of the invention, the nozzle 302 of the nozzle array has an aperture of 10 micrometers to 50 micrometers, and the nozzle 302 sprays the organic resin 403 in a pulse mode.
[0062] The volume of the organic resin 403 droplets sprayed by the nozzle 302 is 0.1 pL to 10 pL, the spraying pressure is 10 kPa to 50 kPa, and the frequency is 1 kHz to 10 kHz.
[0063] In some embodiments, the organic resin 403 comprises 5 wt% to 15 wt% of nano-silica and 1 wt% to 5 wt% of carbon nanotubes.
[0064] like Figure 5B The diagram shown is a schematic diagram of the structure of the interlayer gap filling device after filling the interlayer gap in an embodiment of the present invention. It can be seen that the organic resin 403 is only filled in the interlayer gap 402, and there is no organic resin 403 on the outside of the interlayer gap 402. Therefore, it can save materials and does not require photolithography or etching process to remove the organic resin 403 on the outside of the interlayer gap 402, so the process is simple.
[0065] The ultraviolet LED array 303 is used for ultraviolet curing of the organic resin 403. For example... Figure 4CThe diagram shown is a schematic diagram of the UV curing process.
[0066] The motion mechanism 304, the nozzle array, the gap detection module 301 and the ultraviolet LED array 303 are all mounted on the motion mechanism 304.
[0067] An adaptive motion control system is used to control the motion mechanism 304 to move and drive the nozzle array, the gap detection module 301 and the ultraviolet LED array 303 to move. Based on the real-time three-dimensional coordinates of the interlayer gap 402 obtained by the gap detection module 301, the motion mechanism 304 is controlled to drive the nozzle array to move along the path of the interlayer gap 402 to achieve selective filling of the interlayer gap 402.
[0068] In this embodiment of the invention, the ultraviolet LED array 303 and the nozzle array move synchronously to achieve synchronous ultraviolet curing of the filled organic resin 403, that is, the ultraviolet curing is in-situ curing. In some embodiments, the wavelength of the light emitted by the ultraviolet LED array 303 is 365nm, which follows the synchronous radiation of the nozzle to achieve material pre-curing, that is, ultraviolet curing, and the ultraviolet curing time is <1 second.
[0069] In this embodiment of the invention, the motion mechanism 304 includes a six-axis robotic arm, which drives the spraying path along the interlayer gap 402 of the nozzle array. The positioning accuracy of the spraying path is ±0.5 micrometers. In some embodiments, an infrared sensor is also integrated on the nozzle 302 to correct the position of the interlayer gap 402 in real time.
[0070] In this embodiment of the invention, the detection and positioning of the interlayer gap 402 by the gap detection module 301 and the control of the motion mechanism 304 by the adaptive motion control system enable the organic resin 403 to fill only the interlayer gap 402. This achieves selective filling of the interlayer gap 402, thereby preventing the organic resin 403 from filling outside the interlayer gap 402 and improving material utilization and reducing the amount of organic resin 403 used. For example, compared with the existing method, the amount of organic resin 403 used in this embodiment of the invention can be reduced by 80%.
[0071] In this embodiment of the invention, a nozzle array consisting of multiple nozzles 302 is used to spray organic resin 403. The orifice diameter of the nozzles 302 can be set to a smaller value. Combined with the setting of the spraying mode, such as pulse mode spraying, the filling quality can be improved, the aspect ratio that can be filled can be increased, and the filling void rate can be reduced. For example, the maximum aspect ratio that can achieve good filling can reach 20:1, while the aspect ratio supported by the existing method is less than 5:1. The void rate after filling in this embodiment of the invention is less than 0.5%, while the void rate of the existing method is greater than 10%.
[0072] Since the embodiments of the present invention do not fill the outer layer gap 402 with organic resin 403, there is no need to add additional photolithography or etching to remove excess organic resin 403. Therefore, the embodiments of the present invention can simplify the filling process.
[0073] The embodiments of the present invention also have the characteristics of strong compatibility, including: supporting flexible substrates (such as PI thin films) and heterogeneous integration (silicon + glass); adapting to TSV exposed structures to avoid the chip (die) filling material covering the conductive channels.
[0074] The method for filling interlayer gaps 402 in this embodiment of the invention includes the following steps:
[0075] The gap detection module 301 is used to detect and locate the interlayer gaps 402.
[0076] In the method of this embodiment of the invention, the interlayer gap 402 is the gap after chip bonding.
[0077] The gap detection module 301 uses an optical microscope or laser scanning equipment to obtain the three-dimensional coordinates of the interlayer gap 402.
[0078] Organic resin 403 is sprayed to fill the interlayer gaps 402 using a nozzle array consisting of multiple nozzles 302.
[0079] In the method of this embodiment, the nozzle 302 of the nozzle array has an aperture of 10 micrometers to 50 micrometers, and the nozzle 302 sprays the filling material in a pulse mode.
[0080] The volume of the droplets of the filler material sprayed by the nozzle 302 is 0.1 pL to 10 pL, the spraying pressure is 10 kPa to 50 kPa, and the frequency is 1 kHz to 10 kHz.
[0081] The organic resin 403 comprises 5 wt% to 15 wt% nano-silica and 1 wt% to 5 wt% carbon nanotubes.
[0082] The filling material is cured under ultraviolet light using an ultraviolet LED array 303.
[0083] The nozzle array, the gap detection module 301, and the ultraviolet LED array 303 are all mounted on the motion mechanism 304. An adaptive motion control system controls the motion mechanism 304 to move and drive the nozzle array, the gap detection module 301, and the ultraviolet LED array 303 to move. Based on the real-time three-dimensional coordinates of the interlayer gap 402 obtained by the gap detection module 301, the motion mechanism 304 is controlled to drive the nozzle array to move along the path of the interlayer gap 402 to achieve selective filling of the interlayer gap 402.
[0084] In the method of this invention, the ultraviolet LED array 303 and the nozzle array move synchronously to achieve synchronous ultraviolet curing of the filled organic resin 403. In some embodiments, the wavelength of the light emitted by the ultraviolet LED array 303 is 365 nm, and the ultraviolet curing time is <1 second.
[0085] In the method of this embodiment of the invention, the motion mechanism 304 includes a six-axis robotic arm, and the spraying path along which the nozzle array moves along the interlayer gap 402 is driven by the six-axis robotic arm. The positioning accuracy of the spraying path is ±0.5 micrometers.
[0086] The nozzle 302 also integrates an infrared sensor to correct the position of the interlayer gap 402 in real time.
[0087] After all the interlayer gaps 402 have been filled, the process further includes:
[0088] The organic resin 403 is thermocured by baking. In some embodiments, the thermocure is achieved by post-baking heat treatment at a temperature of 120°C for 10 minutes to complete the final crosslinking.
[0089] This invention, through the setting of a high-precision micro-nozzle array and the combination of real-time gap detection and motion control, directly sprays the filling material only in the gap area after die bonding, avoiding full-area coating, and significantly improving material utilization and filling quality.
[0090] Taking the interlayer gap 402, which has a filling stack structure of 8 dies, a single layer thickness of 50 μm, and a gap width of 10 μm, as an example, the method of the present invention can adopt steps including the following specific parameters:
[0091] The gaps are detected and located by using an optical microscope or laser scanning to obtain the three-dimensional coordinates of the gaps between layers.
[0092] The process of spraying organic resin into the crevices includes: a nozzle orifice diameter of 20 μm, a pressure of 30 kPa, and a frequency of 5 kHz; the organic resin is an epoxy resin with a viscosity of 120 cP.
[0093] The light power density in the UV curing, i.e., pre-curing, is 50 mW / cm². 2 The time is 0.5s.
[0094] The temperature for the thermosetting baking heat treatment is 120°C and the time is 8 minutes.
[0095] The method described in this invention showed no delamination after thermal cycling testing; it had a high fill rate with no voids, low material consumption, and reduced costs by 65%.
[0096] The present invention has been described in detail above through specific embodiments, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.
Claims
1. An interlayer gap filling apparatus characterized by, The application relates to a chip bonding method, comprising the following steps: a gap detection module is used to detect and locate an interlayer gap; a nozzle array composed of multiple nozzles is used to spray organic resin to fill the interlayer gap; an ultraviolet LED array is used to ultraviolet cure the organic resin; a motion mechanism is used to arrange the nozzle array, the gap detection module and the ultraviolet LED array on the motion mechanism; an adaptive motion control system is used to control the motion mechanism to move the nozzle array, the gap detection module and the ultraviolet LED array, and according to the three-dimensional coordinates of the real-time location of the interlayer gap obtained by the gap detection module, the motion mechanism is controlled to drive the nozzle array to move along the path of the interlayer gap to realize selective filling of the interlayer gap.
2. The interlayer gap filling apparatus of claim 1, wherein: The interlayer gap is a gap after chip bonding.
3. The apparatus of claim 1, wherein: The gap detection module uses an optical microscope or a laser scanning device to obtain the three-dimensional coordinates of the interlayer gap.
4. The interlayer gap filling apparatus of claim 3, wherein: The ultraviolet LED array and the nozzle array are synchronously moved to realize synchronous ultraviolet curing of the filled organic resin.
5. The apparatus of claim 1, wherein: The nozzle aperture of the nozzle array is 10-50 microns, and the nozzle sprays the organic resin in a pulse mode; The droplet volume of the organic resin sprayed by the nozzle is 0.1-10 pL, the spraying pressure is 10-50 kPa, and the frequency is 1-10 kHz.
6. The apparatus of claim 1, wherein: The organic resin comprises 5-15 wt% nanosilica and 1-5 wt% carbon nanotubes.
7. The apparatus of claim 4, wherein: The motion mechanism comprises a six-axis mechanical arm, and the spraying path of the movement of the nozzle array along the interlayer gap is driven by the six-axis mechanical arm, and the positioning accuracy of the spraying path is + / -0.5 microns.
8. The apparatus of claim 7, wherein: An infrared sensor is integrated on the nozzle to correct the position of the interlayer gap in real time.
9. An interlayer gap filling method characterized by, The application further relates to a chip bonding method, comprising the following steps: a gap detection module is used to detect and locate an interlayer gap; a nozzle array composed of multiple nozzles is used to spray organic resin to fill the interlayer gap; an ultraviolet LED array is used to ultraviolet cure the filled material; the nozzle array, the gap detection module and the ultraviolet LED array are arranged on a motion mechanism, and an adaptive motion control system is used to control the motion mechanism to move the nozzle array, the gap detection module and the ultraviolet LED array, and according to the three-dimensional coordinates of the real-time location of the interlayer gap obtained by the gap detection module, the motion mechanism is controlled to drive the nozzle array to move along the path of the interlayer gap to realize selective filling of the interlayer gap.
10. The interlayer gap filling method according to claim 9, wherein: The interlayer gap is a gap after chip bonding.
11. The interlayer gap filling method according to claim 9, wherein: The gap detection module uses an optical microscope or a laser scanning device to obtain the three-dimensional coordinates of the interlayer gap.
12. The interlayer gap filling method according to claim 11, wherein: The ultraviolet LED array and the nozzle array are synchronously moved to realize synchronous ultraviolet curing of the filled organic resin.
13. The interlayer gap filling method according to claim 9, wherein: The nozzle aperture of the nozzle array is 10-50 microns, and the nozzle sprays the filling material in a pulse mode; The droplet volume of the filling material sprayed by the nozzle is 0.1-10 pL, the spraying pressure is 10-50 kPa, and the frequency is 1-10 kHz.
14. The interlayer gap filling method of claim 9, wherein: The organic resin comprises 5-15 wt% of nano-silica and 1-5 wt% of carbon nanotubes.
15. The interlayer gap filling method of claim 12, wherein: The motion mechanism comprises a six-axis mechanical arm, and a spraying path of the movement of the nozzle array along the interlayer gap is driven by the six-axis mechanical arm, and the positioning accuracy of the spraying path is ±0.5 microns.
16. The interlayer gap filling method of claim 15, wherein: The nozzle is further integrated with an infrared sensor to correct the position of the interlayer gap in real time.
17. The interlayer gap filling method of claim 9, wherein: After filling all the interlayer gaps, it further comprises: The organic resin is heat-cured by baking.