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CN-121772710-B - Preparation method of SOI material and SOI wafer

CN121772710BCN 121772710 BCN121772710 BCN 121772710BCN-121772710-B

Abstract

The invention belongs to the technical field of semiconductor processing and manufacturing, and provides a preparation method of an SOI material and an SOI wafer, wherein the preparation method comprises the steps of sequentially preparing an aluminum nitride layer, an aluminum oxide layer and top silicon on a first substrate to obtain a first bonding body; providing a support substrate with an oxygen buried layer as a second bonding body, bonding the first bonding body and the second bonding body to obtain a bonding structure, and sequentially removing the first substrate, the aluminum nitride layer and the aluminum oxide layer in the bonding structure to expose top silicon to obtain the SOI material. The ion implantation process is replaced and omitted by collocation of epitaxial growth, bonding and removal processes, so that performance problems caused by introducing various defects can be avoided, accurate control of the thickness of top silicon and the quality of an oxygen-buried layer is facilitated, complexity of procedures and process cost are reduced, and the method is particularly suitable for mass production of large-size SOI wafers with the thickness of 300mm and above.

Inventors

  • HU ZHIFENG
  • GAO WENLIN
  • LIU FUCHAO
  • MU FENGWEN

Assignees

  • 青禾晶元(天津)半导体材料有限公司

Dates

Publication Date
20260508
Application Date
20260302

Claims (10)

  1. 1. The preparation method of the SOI material is characterized by comprising the following steps of: Providing a first substrate, and sequentially preparing an aluminum nitride layer, an aluminum oxide layer and top silicon on the first substrate to obtain a first bonding body; providing a support substrate provided with an oxygen-buried layer as a second bond; contacting the surface of the top silicon layer with the surface of the oxygen-buried layer, and bonding the first bonding body and the second bonding body to obtain a bonding structure; and sequentially removing the first substrate, the aluminum nitride layer and the aluminum oxide layer in the bonding structure to expose the top silicon layer, thereby obtaining the SOI material.
  2. 2. The method of claim 1, wherein the method of forming the aluminum nitride layer comprises at least one of metal organic chemical vapor deposition, molecular beam epitaxy, or atomic layer deposition; And/or the thickness of the aluminum nitride layer is 10 nm-200 nm.
  3. 3. The method of claim 1, wherein the method of forming the aluminum oxide layer comprises at least one of metal organic chemical vapor deposition, molecular beam epitaxy, or atomic layer deposition; and/or the thickness of the alumina layer is 50 nm-500 nm; and/or, the top layer silicon comprises a monocrystalline silicon layer, and the method for preparing and forming the monocrystalline silicon layer comprises metal organic chemical vapor deposition; and/or the thickness of the top layer silicon is 5 nm-20 mu m.
  4. 4. The method of claim 1, wherein the first substrate comprises a first silicon wafer; and/or the diameter of the first substrate is 200 nm-450 nm; and/or the support substrate comprises a second silicon wafer comprising monocrystalline silicon; and/or the diameter of the supporting substrate is 200 nm-450 nm, and is the same as the diameter of the first substrate.
  5. 5. The method for producing an SOI material according to claim 1, wherein the method for providing the buried oxide layer on the supporting substrate comprises providing a supporting substrate, performing thermal oxidation and/or deposition on a surface of the supporting substrate, and forming a buried oxide layer; and/or the thickness of the oxygen-buried layer is 10 nm-10 μm.
  6. 6. The method of claim 1, wherein the bonding means comprises hydrophilic bonding and/or room temperature activated bonding.
  7. 7. The method of claim 1, wherein the removing the first substrate comprises mechanical polishing and/or chemical mechanical polishing.
  8. 8. The method of claim 1, wherein the method of removing the aluminum nitride layer satisfies at least one of the following conditions: (A1) The method for removing the aluminum nitride layer is a first etching process, wherein the first etching process comprises a first wet etching process and/or a plasma dry etching process; (A2) The etching solution of the first wet etching comprises tetramethyl ammonium hydroxide and/or potassium hydroxide; (A3) The process gas of the plasma dry etching comprises chlorine and/or boron trichloride; (A4) In the first etching process, the etching selectivity ratio of the aluminum nitride layer to the aluminum oxide layer is greater than 100:1.
  9. 9. The method of claim 1, wherein the method of removing the alumina layer satisfies at least one of the following conditions: (B1) The method for removing the aluminum oxide layer is a second etching process, wherein the second etching process comprises a second wet etching process; (B2) The etching solution of the second wet etching comprises a hot phosphoric acid solution; (B3) In the second etching process, the etching selectivity ratio of the aluminum oxide layer to the top silicon is greater than 1000:1.
  10. 10. An SOI wafer obtained by the method according to any one of claims 1 to 9, wherein the thickness uniformity of the top silicon layer is not more than ±2% over the whole wafer, and the interface state density between the top silicon layer and the buried oxide layer is lower than 1×10 11 eV -1 ·cm -2 .

Description

Preparation method of SOI material and SOI wafer Technical Field The invention belongs to the technical field of semiconductor manufacturing and processing, and relates to a preparation method of an SOI material and an SOI wafer. Background The SOI technology can realize dielectric isolation between devices by introducing an insulating buried oxide layer (Buried Oxide, BOX) between a silicon substrate and top silicon, effectively reduce parasitic capacitance, leakage current and latch-up effect, and can remarkably improve the speed, power consumption and irradiation resistance of an integrated circuit. As semiconductor devices move toward smaller nodes and higher performance, there is an increasing demand for SOI materials with large dimensions (e.g., 300mm, 450 mm), ultra-thin top-layer silicon, and high quality buried oxide interfaces. At present, the SOI preparation technology can form an oxygen buried layer by adopting a mode of high-dose oxygen ion implantation and high-temperature annealing, but the scheme has the problems of high cost, high defect density and difficulty in preparing ultrathin top-layer silicon. In addition, SOI can be prepared by hydrogen ion implantation, bonding and cracking, but this approach, while achieving high quality top silicon in small scale production, presents significant challenges in achieving uniform hydrogen ion implantation and precise control of cracking on large-scale wafers, and is complex in process and costly. In addition, the two methods are easy to introduce higher defect density at the interface between the top silicon layer and the buried oxide layer in the preparation process. Therefore, a new solution is needed to overcome the above-mentioned drawbacks, and is suitable for large-sized wafers, and can precisely control the thickness of the top silicon layer and have high interface quality. Disclosure of Invention In view of the problems existing in the prior art, the present invention aims to provide a preparation method of an SOI material and an SOI wafer, so as to realize high-quality and low-cost manufacture of a large-size SOI material. To achieve the purpose, the invention adopts the following technology: In a first aspect, the present invention provides a method for preparing an SOI material, the method comprising the steps of: providing a first substrate, and sequentially preparing an aluminum nitride layer (namely an AlN layer), an aluminum oxide layer (namely an Al 2O3 layer) and top silicon on the first substrate to obtain a first bonding body; providing a support substrate provided with an oxygen-buried layer as a second bond; contacting the surface of the top silicon layer with the surface of the oxygen-buried layer, and bonding the first bonding body and the second bonding body to obtain a bonding structure; and sequentially removing the first substrate, the aluminum nitride layer and the aluminum oxide layer in the bonding structure to expose the top silicon layer, thereby obtaining the SOI material. The preparation method comprises the steps of heteroepitaxially growing an aluminum nitrogen layer serving as an etching barrier layer and an aluminum oxide layer serving as a sacrificial layer on a first substrate, enabling the sacrificial layer to support epitaxial growth of a device-level top silicon film on the surface of the sacrificial layer, bonding the structure with another substrate with an oxygen-buried layer through a bonding technology, removing the first substrate silicon wafer to expose the etching barrier layer, removing the etching barrier layer to release the sacrificial layer below, and finally removing the sacrificial layer to expose ultra-flat top silicon with low defect density, wherein the rest of top silicon/oxygen-buried layer/supporting silicon structure is the SOI material. The preparation method can avoid various problems caused by the ion implantation process through the epitaxial growth and removal process, is beneficial to realizing the accurate control of the thickness of the top silicon and the quality of the buried oxide layer, and is particularly suitable for the mass production of large-size SOI wafers with the thickness of 300mm and above. The following technical scheme is a preferred technical scheme of the invention, but is not a limitation of the technical scheme provided by the invention, and the technical purpose and beneficial effects of the invention can be better achieved and realized through the following technical scheme. As a preferred embodiment of the present invention, the method for preparing the aluminum nitride layer includes at least one of Metal Organic Chemical Vapor Deposition (MOCVD), molecular Beam Epitaxy (MBE), or Atomic Layer Deposition (ALD). As a preferable technical scheme of the invention, the thickness of the aluminum nitride layer is 10 nm-200 nm. Illustratively, it may be 10nm, 30nm, 50nm, 80nm, 100nm, 120nm, 140nm, 160nm, 180nm or 200nm, etc. As a preferred embodiment of the pr