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CN-122003144-A - TSV structure with diamond insulating layer, interposer and preparation method

CN122003144ACN 122003144 ACN122003144 ACN 122003144ACN-122003144-A

Abstract

The invention relates to the technical field of chip packaging, and provides a TSV structure with a diamond insulating layer, an interposer and a preparation method. The diamond is taken as the insulating layer to be incorporated into the structure of the intermediate layer, so that the overall heat dissipation performance of the intermediate layer can be enhanced on the premise of ensuring the insulating function, local hot spot formation and corresponding electric and physical damages to the chip are prevented, an additional heat dissipation structure is not required to be added, the area of the chip is not additionally occupied, the processing difficulty and the cost are lower, and the method has the potential of industrialized popularization and application.

Inventors

  • YU DAQUAN
  • ZHU YUNTING
  • You Yicheng

Assignees

  • 厦门大学

Dates

Publication Date
20260508
Application Date
20260211

Claims (10)

  1. 1. A TSV structure with diamond insulating layer, comprising: a silicon substrate, wherein a through hole is formed in the silicon substrate; the diamond insulating layer is arranged on the upper surface of the silicon substrate and the inner wall of the through hole; The blocking layer is arranged on the surface of the diamond insulating layer on the inner wall of the through hole; and the metal filling layer is filled in the through hole.
  2. 2. The TSV structure with diamond insulating layer structure according to claim 1, wherein the thickness of the diamond insulating layer is 0.1-5 μm.
  3. 3. The TSV structure with the diamond insulating layer according to claim 1, wherein the barrier layer is one or more of Ti, tiN, ta and TaN, and the thickness of the barrier layer is 0.1-0.8 μm.
  4. 4. The TSV structure with diamond insulation layer of claim 1 wherein the metal filler layer is copper.
  5. 5. An interposer based TSV structure with diamond insulation layer, comprising: A TSV structure with diamond insulation layer according to any one of claims 1-4; the rewiring layer is arranged on the front surface of the TSV structure with the diamond insulating layer and comprises a passivation layer and rewiring distributed in the passivation layer; the back passivation layer is arranged on the back surface of the TSV structure with the diamond insulating layer; the bump structure comprises a front bump structure and a back bump structure, the front bump structure is arranged on the surface of the rewiring layer and is electrically connected with the rewiring layer, and the back bump structure is arranged on the back of the TSV structure with the diamond insulating layer and is electrically connected with the metal filling layer in the through hole.
  6. 6. The interposer of claim 5, wherein the passivation layer is silicon dioxide or a polymer, and the rewiring is copper.
  7. 7. The interposer of claim 5, wherein the bump structure comprises an under bump metal layer, a metal pillar, and a solder, the under bump metal layer being a Ti/W-Cu composite layer or a Cr-Cu alloy layer, the solder being any one or more of a Sn-Ag alloy, a Sn-Cu alloy, a Sn-Ag-Cu alloy, a Sn-In alloy, a Sn-Bi alloy, and a Sn-Sb alloy, which are sequentially stacked.
  8. 8. The method for preparing the interposer based on the TSV structure with the diamond insulating layer according to any one of claims 5 to 7, which is characterized by comprising the following steps: Etching the silicon substrate to form a blind hole, sequentially depositing a diamond insulating layer, a barrier layer and a metal seed layer, and then filling a metal material into the blind hole through electroplating to form a metal filling layer to obtain a semi-finished product; Performing chemical mechanical polishing on the front surface of the semi-finished product to obtain a flattened semi-finished product; Sequentially preparing a rewiring layer and a front bump structure on the front of the flattened semi-finished product, and bonding a temporary bonding layer on the surface of the front bump structure to obtain a temporary bonding semi-finished product; thinning the back of the temporary bonding semi-finished product to expose the metal filling layer in the through hole, preparing a back passivation layer, perforating the back passivation layer to expose the metal filling layer, and preparing a back bump structure; And removing the temporary bonding layer to obtain the intermediate layer based on the TSV structure with the diamond insulating layer.
  9. 9. The method of claim 8, wherein the method of depositing the diamond insulating layer is a microwave plasma chemical vapor deposition method; Depositing the diamond insulating layer comprises sequentially depositing a nucleation layer and a growth layer; The conditions for depositing the nucleation layer comprise 1700-1800W of microwave power, 50-60 Torr of air pressure in a cavity, 640-660 ℃ of deposition temperature, 4-5% of methane flow, -100-200V of bias voltage and 0.5-2 h of deposition time; The conditions for depositing the growth layer comprise 2200-2500W of microwave power, 80-100 Torr of air pressure in a cavity, 840-860 ℃ of deposition temperature, 1-3% of methane flow rate and 6-12 h of deposition time.
  10. 10. The method for preparing the barrier layer according to claim 8, wherein the method for depositing the barrier layer is a magnetron sputtering method, and the deposition conditions comprise 90-120W of radio frequency power, 25-35 sccm of argon flow, 5-8 nm/min of deposition rate and 80-120 min of deposition time; the method for depositing the metal seed layer is a magnetron sputtering method, and the deposition conditions comprise 90-120W of direct current power, 25-35 sccm of argon flow, 30-40 nm/min of deposition rate and 25-30 min of deposition time.

Description

TSV structure with diamond insulating layer, interposer and preparation method Technical Field The invention relates to the technical field of chip packaging, in particular to a TSV structure with a diamond insulating layer, an interposer and a preparation method. Background Advanced packaging technology is one of the most important ways to promote the continuous improvement of the performance of integrated circuit chips, including 2.5D/3D packaging technology using TSV (Through-Silicon-Via) structures. However, the 2.5D/3D packaging system with high integration has higher heating density per unit volume, and has higher requirements on heat dissipation performance, and the application and miniaturization trend of the high-power device in the system are more challenges for enhancing the heat dissipation problem. The interposer is a critical structure in a 2.5D/3D packaging system, and how to optimize the heat dissipation performance of this structure to achieve efficient thermal management of the system as a whole is a major concern in the art. At present, the thought of optimizing the heat dissipation performance of the interposer mainly comprises the following two steps of (1) replacing silicon with a high heat dissipation semiconductor substrate (such as silicon carbide, diamond and the like), and (2) adding a TSV structure (THERMAL TSV, TTSV for short) which is not used for transporting signals and only used for transporting heat. The large-size semiconductor substrate (such as silicon carbide, diamond, etc.) required by the first method has high wafer cost and high through hole processing difficulty, which limits the popularization and application of the scheme in industry. The second approach, while significantly enhancing heat transfer to the surrounding environment, can result in valuable chip area being consumed and possibly parasitic capacitive coupling with surrounding circuitry, thereby increasing design requirements and difficulty. In summary, how to improve the heat dissipation performance of the interposer without increasing the area, design difficulty and processing difficulty of the additional heat dissipation structure is a technical problem to be solved in the art. Disclosure of Invention In view of this, the present invention provides a TSV structure with a diamond insulating layer, an interposer, and a method of fabrication. According to the invention, diamond is used as the insulating layer to replace the SiO 2 insulating layer in the traditional TSV structure, so that the heat dissipation performance of the intermediate layer can be obviously improved on the basis of not increasing the required area, design difficulty and processing difficulty of the additional heat dissipation structure, and the formation of local hot spots and the corresponding electric and physical damage to the chip are prevented. In order to achieve the above object, the present invention provides the following technical solutions: a TSV structure with diamond insulating layer, comprising: a silicon substrate, wherein a through hole is formed in the silicon substrate; the diamond insulating layer is arranged on the upper surface of the silicon substrate and the inner wall of the through hole; The blocking layer is arranged on the surface of the diamond insulating layer on the inner wall of the through hole; and the metal filling layer is filled in the through hole. Preferably, the thickness of the diamond insulating layer is 0.1-5 μm. Preferably, the blocking layer is one or more of Ti, tiN, ta and a TaN composite layer, and the thickness of the blocking layer is 0.1-0.8 mu m. Preferably, the metal filling layer is made of copper. The invention also provides an interposer based on the TSV structure with the diamond insulating layer, which comprises: The TSV structure with the diamond insulating layer is disclosed in the scheme; the rewiring layer is arranged on the front surface of the TSV structure with the diamond insulating layer and comprises a passivation layer and rewiring distributed in the passivation layer; the back passivation layer is arranged on the back surface of the TSV structure with the diamond insulating layer; the bump structure comprises a front bump structure and a back bump structure, the front bump structure is arranged on the surface of the rewiring layer and is electrically connected with the rewiring layer, and the back bump structure is arranged on the back of the TSV structure with the diamond insulating layer and is electrically connected with the metal filling layer in the through hole. Preferably, the passivation layer is made of silicon dioxide or polymer, and the rewiring layer is made of copper. Preferably, the bump structure comprises an under bump metal layer, a metal column and a solder which are sequentially laminated, wherein the under bump metal layer is a Ti/W-Cu composite layer or a Cr-Cu alloy layer, and the solder is any one or more of Sn-Ag alloy, sn-Cu alloy, sn-Ag-Cu