A process for one-time filling of high aspect ratio TSV with varying diameters and depths.

Abstract

This invention discloses a process for one-time filling of high aspect ratio TSVs with varying apertures. The process includes preparing a substrate wafer and etching various aspect ratio TSV blind vias onto the wafer; depositing a Cu seed layer on the wafer surface (including inside the vias); and using a variable-frequency flow rate method to achieve one-time complete filling of the high aspect ratio TSVs. By employing a variable-frequency flow rate and a frequency-tuned laminar flow plate, an "S"-shaped flow field is formed around the vias on the substrate, thereby intermittently adjusting the additive concentration and Cu ion concentration within each via, ensuring sufficient filling capacity in each via. This simple and effective method achieves complete filling of TSVs with varying aspect ratios, solving the problem of seed layer damage caused by multiple step-by-step filling in existing processes, as well as the process complexity caused by step-by-step processes. Simultaneously, it achieves one-time complete filling of high aspect ratio TSVs with varying apertures, effectively improving work efficiency and reducing process costs.

Description

Technical Field

[0001] This invention relates to a process for filling TSVs with irregular apertures, specifically a method for one-time filling of TSVs with high aspect ratio irregular apertures, belonging to the field of semiconductor manufacturing technology. Background Technology

[0002] With the development of the semiconductor field, the requirements for packaging systems have gradually shifted from two-dimensional planar structures to three-dimensional vertical structures. TSV filling technology enables vertical interconnection and plays a crucial role in three-dimensional packaging; while the complete filling of TSVs with different vias on the same layer can effectively solve the problem of functional connection between the loaded chip and chips on different layers, thereby realizing a better development of packaging systems from 2D to 3D systems.

[0003] However, the difficulties in filling TSVs with high aspect ratios and irregular holes are: (1) the electric field distribution inside the holes of high aspect ratio deep hole electroplating is an abnormal electric field distribution; (2) the distribution of various components of the chemical solution inside the holes is also a non-static distribution. In order to achieve the filling of TSVs with irregular holes, the existing process often uses dry film patterning to open one type of hole, and then performs single-hole electroplating. After the complete filling is completed, other hole structures are filled in sequence in the same way. This process method increases the complexity of the process and the processing time by adding multiple process steps. At the same time, the seed layer is often damaged in the multi-step process, which leads to filling defects in the electroplating filling.

[0004] In view of this, it is necessary to seek a process method that is simple to control, low in cost, and highly selective, so as to solve the above technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a process method for one-time filling of high aspect ratio TSV with irregular holes in order to solve at least one of the above-mentioned technical problems.

[0006] The present invention achieves the above objectives through the following technical solution: a process for one-time filling of high aspect ratio TSV vias, comprising a substrate material layer, an electroplated filling layer, deep blind vias, and shallow blind vias; the deep blind vias and shallow blind vias are staggered on the substrate material layer, the electroplated filling layer is located on the upper layer of the substrate material layer, and the electroplated filling layer fills the deep blind vias and shallow blind vias completely;

[0007] Its process includes the following steps:

[0008] Step 1: Prepare the substrate. Prepare a circular substrate using a patterned etching process, and etch TSV blind vias with various aspect ratios on the substrate.

[0009] Step 2: After wet cleaning of the substrate, a seed layer is sputtered onto the surface of the substrate wafer and inside the blind holes.

[0010] Step 3: Exchange chemicals in the orifice by using staged variable frequency flow rate and adjusting the amplitude of laminar flow plate;

[0011] Step 4: By adopting the radio frequency pulse electroplating mode, the TSV structure with irregular holes is completely filled by one-time electroplating, and the metal filling is performed in one step.

[0012] As a further aspect of the present invention: in step one, the substrate is Si or glass (quartz).

[0013] As a further aspect of the present invention: in step one, the aperture-to-depth ratio of the TSV blind hole is 1:5-1:11, and the maximum depth inside the hole is 220μm.

[0014] As a further aspect of the present invention: in step one, the TSV blind via is formed by etching 2-4 different diameter-to-depth ratios on the same substrate.

[0015] As a further aspect of the present invention: in step three, the frequency of the stage variable frequency flow rate is 2-40 min / time.

[0016] As a further aspect of the present invention: in step three, the flow rate of the stage variable frequency flow rate is 5-40 L / min.

[0017] As a further aspect of the present invention: in step three, when exchanging the chemical solution inside the hole, an oscillating laminar flow plate is added between the cathode and the anode.

[0018] As a further aspect of the present invention: in step three, the laminar flow plate contains small holes with a diameter of 5mm-2cm that are evenly distributed, and the diameter of the holes in the plate is adjustable.

[0019] As a further aspect of the present invention: in step three, the laminar flow plate oscillation speed is 1-100 times / min.

[0020] The beneficial effects of this invention are:

[0021] 1. By adjusting the flow rate through variable frequency and adding laminar flow regulating plates with different orifice shapes between the anode and cathode, the flow field within the orifice is regulated, causing an "S"-shaped micro-vortex to form on the cathode surface. This allows for real-time adjustment of the additives and Cu ions within the orifice, ensuring that all components are effectively replenished and maintaining the effective proportion of the effective components during the filling process. Simultaneously, the variable frequency flow rate also indirectly regulates the dynamic distribution of the electric field, adjusting the filling effect during the electric field change process.

[0022] 2. By using a variable frequency flow rate to intermittently adjust the additive concentration and Cu ion concentration in different pores, the filling capacity of various pores can be fully utilized. This method achieves complete filling of TSVs with different diameter-to-depth ratios in a simple and effective manner, solving the problem of seed layer damage caused by multiple steps in the existing process, as well as the process complexity caused by step-by-step processes. At the same time, it completes the problem of one-time complete filling of TSVs with high diameter-to-depth ratios, effectively improving work efficiency and reducing process costs. Attached Figure Description

[0023] Figure 1 This is a flowchart of the process method of the present invention;

[0024] Figure 2 This is a side view of the filled and layered structure of the present invention;

[0025] Figure 3 Fill in the side view of the example of the present invention;

[0026] Figure 4 This is a top view of the laminar flow plate;

[0027] Figure 5 This is a diagram illustrating the pulse electroplating power application mode.

[0028] In the figure: 1. Substrate material layer, 2. Electroplated filler layer, 3. Deep blind via, 4. Shallow blind via. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] like Figures 1 to 5 As shown, a process for one-time filling of high aspect ratio TSV (Through-Silicon Vias) includes a substrate material layer 1, an electroplated filling layer 2, a deep blind via 3, and a shallow blind via 4; the deep blind via 3 and the shallow blind via 4 are staggered on the substrate material layer 1, the electroplated filling layer 2 is located on the upper layer of the substrate material layer 1, and the electroplated filling layer 2 completely fills the deep blind via 3 and the shallow blind via 4.

[0032] Its process includes the following steps:

[0033] Step 1: Prepare the substrate. Prepare a circular substrate using a patterned etching process, and etch TSV blind vias with various aspect ratios on the substrate.

[0034] Step 2: After wet cleaning of the substrate, a seed layer is sputtered onto the surface of the substrate wafer and inside the blind holes.

[0035] Step 3: Exchange chemicals in the orifice by using staged variable frequency flow rate and adjusting the amplitude of laminar flow plate;

[0036] Step 4: By adopting the radio frequency pulse electroplating mode, the TSV structure with irregular holes is completely filled by one-time electroplating, and the metal filling is performed in one step.

[0037] In this embodiment of the invention, in step one, the substrate is Si or glass (quartz).

[0038] In this embodiment of the invention, in step one, the diameter-to-depth ratio of the TSV blind hole is 1:5-1:11, and the maximum depth inside the hole is 220μm.

[0039] In this embodiment of the invention, in step one, the TSV blind via is formed by etching 2-4 different diameter-to-depth ratio vias on the same substrate.

[0040] In this embodiment of the invention, in step three, the frequency of the stage variable frequency flow rate is 2-40 min / time.

[0041] In this embodiment of the invention, in step three, the flow rate of the stage variable frequency flow rate is 5-40 L / min.

[0042] In this embodiment of the invention, during step three, when exchanging the chemical solution inside the hole, an oscillating laminar flow plate is added between the cathode and the anode.

[0043] In this embodiment of the invention, in step three, the laminar flow plate contains small holes with a diameter of 5mm-2cm that are evenly distributed, and the diameter of the holes in the plate is adjustable.

[0044] In this embodiment of the invention, in step three, the laminar flow plate oscillation speed is 1-100 times / min.

[0045] Example 2

[0046] A process for one-time filling of high aspect ratio TSV (transient vacuum veneer) holes includes the following steps:

[0047] Step 1: Provide a substrate material, which is (100) type silicon, and use laser etching to form two hole types with a diameter-to-depth ratio of 30:100 and 30:200 on the substrate;

[0048] Step 2: After wet cleaning and etching, a 2μm Cu seed layer is grown on the surface of the wafer (including inside the holes) by PVD.

[0049] Step 3: Using a copper sulfate electroplating solution, the flow rate is switched between 10 L / min and 15 L / min at a frequency of 10 min / time. The laminar flow plate has an orifice diameter of 5 mm and an oscillation frequency of 25 times / min.

[0050] Step 4: The electroplating current is 0.9A, the total electroplating time is 4 hours, and the pulse ratio is 1:2.5, that is, 10 seconds of charging and 25 seconds of de-energization.

[0051] Example 3

[0052] A process for one-time filling of high aspect ratio TSV (transient vacuum veneer) holes includes the following steps:

[0053] Step 1: Provide a substrate material, which is a glass substrate, and use dry etching to form three hole types with aspect ratios of 20:50, 20:100 and 20:200 on the substrate.

[0054] Step 2: After wet cleaning and etching, a 2μm Cu seed layer is grown on the surface of the wafer (including inside the holes) by PVD.

[0055] Step 3: Using a copper sulfate electroplating solution, the flow rate is switched at 10L / min, 15L / min and 20L / min at a frequency of 5min / time. The laminar flow plate has an aperture of 8mm and an oscillation frequency of 35 times / min.

[0056] Step 4: The electroplating current is 0.9A, the total electroplating time is 4 hours, and the pulse ratio is 1:2.5, that is, 10 seconds of charging and 25 seconds of de-energization.

[0057] Working principle: By adjusting the flow rate of the variable frequency flow rate, the flow field flow rate in the pore is adjusted in real time, thereby effectively replenishing the components in the pore and ensuring the effective proportion of effective components in the pore during the filling process; at the same time, the variable frequency flow rate also indirectly plays a role in adjusting the dynamic distribution of the electric field and adjusting the filling effect during the change of the electric field.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A process for one-time filling of high aspect ratio TSV with varying diameters and depths, characterized in that: It includes a substrate material layer (1), an electroplated filling layer (2), a deep blind hole (3), and a shallow blind hole (4); the deep blind hole (3) and the shallow blind hole (4) are staggered on the substrate material layer (1), the electroplated filling layer (2) is located on the upper layer of the substrate material layer (1), and the electroplated filling layer (2) fills the deep blind hole (3) and the shallow blind hole (4). Its process includes the following steps: Step 1: Prepare the substrate. Prepare a circular substrate using a patterned etching process, and etch TSV blind vias with various aspect ratios on the substrate. Step 2: After wet cleaning of the substrate, a seed layer is sputtered onto the surface of the substrate wafer and inside the blind holes. Step 3: The chemical exchange in the well is carried out by adjusting the flow rate and the oscillating plate in stages; The frequency of the flow rate variation is 2-40 min / cycle, and the flow rate is 5-40 L / min. When performing in-hole chemical exchange, a swing plate is added between the cathode and the anode. The swing plate contains small holes with a diameter of 5mm-2cm that are evenly distributed, and the diameter of the holes in the plate is adjustable. The swing speed of the swing plate is 1-100 times / min. Step 4: By adopting the radio frequency pulse electroplating mode, the TSV structure with irregular holes is completely filled by one-time electroplating, and the metal filling is performed in one step.

2. The process for one-time filling of high aspect ratio TSV with varying apertures according to claim 1, characterized in that: In step one, the substrate is Si or glass.

3. The process for one-time filling of high aspect ratio TSV with varying apertures according to claim 1, characterized in that: In step one, the diameter-to-depth ratio of the TSV blind hole is 1:5-1:11, and the maximum depth inside the hole is 220μm.

4. The process for one-time filling of high aspect ratio TSV with varying diameters and depths according to claim 1, characterized in that: In step one, the TSV blind via is formed by etching 2-4 different diameter-to-depth ratios on the same substrate.

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