Patents by Inventor Lieng Loo

Lieng Loo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20240372528
    Abstract: An acoustic resonator and a manufacture method thereof. The acoustic resonator includes: a substrate having cavities; piezoelectric units one by one corresponding to the cavities, the piezoelectric units cover the cavities, and each piezoelectric unit includes a first electrode layer, a piezoelectric layer and a second electrode layer sequentially stacked from bottom to top; a protective layer stacked on the piezoelectric unit; a series unit having one end electrically connected to the first electrode layer of one of the piezoelectric units, and the other end electrically connected to the second electrode layer of another one of the piezoelectric units, so as to connect the two piezoelectric units in series. Compared with the 10 related art, the piezoelectric unit is protected from further risk of damages in subsequent manufacturing processes by providing a protective layer on the piezoelectric unit, so that the acoustic resonator has better Q value and coupling coefficient.
    Type: Application
    Filed: May 7, 2023
    Publication date: November 7, 2024
    Inventors: DongLiang Pang, LiEng Loo, Kahkeen Lai, Ke Wu, ShirNee Yap
  • Publication number: 20240372519
    Abstract: The method for fabricating a FBAR provided according to the present invention includes providing a substrate, forming a dielectric material layer on a surface of the substrate away from the substrate, forming a bottom electrode on a surface of the dielectric material layer away from the substrate, forming a piezoelectric material layer on a surface of the bottom electrode away from the substrate, forming an intermediate metal layer on a surface of the piezoelectric material layer away from the substrate, forming a mass load layer on a surface of the intermediate metal layer away from the substrate, and forming a top electrode on a surface of the mass load layer away from the substrate. In this way, process choices are increased, and flexibility in multiple mass load formation of the FBAR below top electrode and in a filter having the FBARs are increased, thereby improving sensitivity in the filter.
    Type: Application
    Filed: May 6, 2023
    Publication date: November 7, 2024
    Inventors: LiEng Loo, Ke Wu, Kahkeen Lai
  • Patent number: 11569791
    Abstract: The invention provides a planarization method, which can make the local flatness of the product to be processed more uniform. The product has a cavity filled with oxide and includes a first electrode layer, a piezoelectric layer and a second electrode layer superposed on the cavity. The first electrode layer covers the cavity and includes a first inclined face around the first electrode layer, and the piezoelectric layer covers the first electrode layer and is arranged on the first electrode layer. The planarization method includes: depositing a passivation layer on the second electrode layer and etching the passivation layer completely until the thickness of the passivation layer is reduced to the required thickness.
    Type: Grant
    Filed: December 29, 2020
    Date of Patent: January 31, 2023
    Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.
    Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
  • Patent number: 11482664
    Abstract: The invention provides a planarization method, which can make the local flatness of the product to be processed more uniform. The product has a cavity filled with oxide and includes a first electrode layer, a piezoelectric layer and a second electrode layer superposed on the cavity. The first electrode layer covers the cavity and includes a first inclined face around the first electrode layer, and the piezoelectric layer covers the first electrode layer and is arranged on the first electrode layer. The planarization method includes: depositing a passivation layer on the second electrode layer and etching the passivation layer completely until the thickness of the passivation layer is reduced to the required thickness.
    Type: Grant
    Filed: December 29, 2020
    Date of Patent: October 25, 2022
    Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.
    Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
  • Patent number: 11305988
    Abstract: Provided are a method for preparing a silicon wafer with a rough surface and a silicon wafer, which solves the problem in the prior art that viscous force is likely to be generated. The method includes: depositing a first film layer having a large surface roughness on a surface of a silicon wafer that has been subjected to planar planarization, and then blanket etching the first film layer to remove the first film layer. Then, the surface of the first silicon layer facing away from the substrate is further etched to form grooves and protrusions, which provide roughness, thereby forming a silicon wafer with a rough surface. When the silicon wafer approaches to another film layer, the viscous force generated therebetween is reduced, and thus the sensitivity of the MEMS device is improved and the probability of out-of-work MEMS device is reduced.
    Type: Grant
    Filed: September 1, 2020
    Date of Patent: April 19, 2022
    Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.
    Inventors: Wooicheang Goh, Lieng Loo, Kahkeen Lai
  • Publication number: 20220063995
    Abstract: Provided are a method for preparing a silicon wafer with a rough surface and a silicon wafer, which solves the problem in the prior art that viscous force is likely to be generated. The method includes: depositing a first film layer having a large surface roughness on a surface of a silicon wafer that has been subjected to planar planarization, and then blanket etching the first film layer to remove the first film layer. Then, the surface of the first silicon layer facing away from the substrate is further etched to form grooves and protrusions, which provide roughness, thereby forming a silicon wafer with a rough surface. When the silicon wafer approaches to another film layer, the viscous force generated therebetween is reduced, and thus the sensitivity of the MEMS device is improved and the probability of out-of-work MEMS device is reduced.
    Type: Application
    Filed: September 1, 2020
    Publication date: March 3, 2022
    Inventors: Wooicheang Goh, Lieng Loo, Kahkeen Lai
  • Patent number: 11192782
    Abstract: Provided are a method for preparing a silicon wafer with a rough surface and a silicon wafer, for solving the problem that a viscous force is likely to be generated when a smooth surface of the silicon wafer approaches another film layer. The method includes: depositing a porous oxide film layer on a surface of the first silicon planar layer that has been subjected to planar planarization, and then etching the porous oxide film layer by XeF2 vapor etching, during which XeF2 gas passes through the porous oxide film layer to etch the first silicon planar layer in an irregular way. Therefore, the first silicon planar layer has a greater surface roughness. When the silicon wafer approaches to another film layer, the viscous force generated therebetween is reduced, improving the sensitivity of the MEMS device and reducing the probability of out-of-work MEMS devices.
    Type: Grant
    Filed: September 1, 2020
    Date of Patent: December 7, 2021
    Assignee: AAC ACOUSTIC TECHNOLOGIES (SHENZHEN) CO., LTD.
    Inventors: Wooicheang Goh, Lieng Loo, Kahkeen Lai
  • Publication number: 20210336125
    Abstract: The invention provides a planarization method, which can make the local flatness of the product to be processed more uniform. The product has a cavity filled with oxide and includes a first electrode layer, a piezoelectric layer and a second electrode layer superposed on the cavity. The first electrode layer covers the cavity and includes a first inclined face around the first electrode layer, and the piezoelectric layer covers the first electrode layer and is arranged on the first electrode layer. The planarization method includes: depositing a passivation layer on the second electrode layer and etching the passivation layer completely until the thickness of the passivation layer is reduced to the required thickness.
    Type: Application
    Filed: December 29, 2020
    Publication date: October 28, 2021
    Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
  • Publication number: 20210336596
    Abstract: The invention provides a planarization method, which can make the local flatness of the product to be processed more uniform. The product has a cavity filled with oxide and includes a first electrode layer, a piezoelectric layer and a second electrode layer superposed on the cavity. The first electrode layer covers the cavity and includes a first inclined face around the first electrode layer, and the piezoelectric layer covers the first electrode layer and is arranged on the first electrode layer. The planarization method includes: depositing a passivation layer on the second electrode layer and etching the passivation layer completely until the thickness of the passivation layer is reduced to the required thickness.
    Type: Application
    Filed: December 29, 2020
    Publication date: October 28, 2021
    Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
  • Patent number: 11111134
    Abstract: The present disclosure provides a method for processing a conductive structure. The method includes the following steps of: forming on a first surface a groove concave from the first surface towards a second surface by means of dry etching; extending the groove from the second surface to form a via through a silicon base; and processing a conductive structure within the via. The method can be applied to a silicon base having a thickness larger than 300 ?m. It breaks the limit on thickness that can be processed in the related art and is capable of providing electrical connectivity on both sides of a silicon base. The method is simple and highly reliable, has high processing efficiency and is applicable to mechanized production.
    Type: Grant
    Filed: January 7, 2019
    Date of Patent: September 7, 2021
    Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.
    Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai, Kianheng Goh
  • Patent number: 10947110
    Abstract: The present invention provides a manufacturing method for MEMS structure. The method includes steps of: S1: providing a substrate, including a structural layer and a silicon-based layer overlapped with the structural layer; S2: carrying out a main etching process for etching out a cavity hole from an end of the silicon-based layer, which is far away from the structural layer, in a direction toward the structural layer until the cavity hole contacts the structural layer; and S3: carrying out an over-etching process for deepening the cavity hole and control an included angle ? between a side wall of the cavity hole and the structural layer to be larger than 10° but smaller than 90°. The invention also provides a MEMS structural and a MEMS microphone manufactured by the method.
    Type: Grant
    Filed: March 25, 2019
    Date of Patent: March 16, 2021
    Assignee: AAC Technologies Pte. Ltd.
    Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai
  • Publication number: 20200357656
    Abstract: The disclosure provides a plane polishing method and a processing method of the silicon wafer. The plane polishing method includes steps of: depositing a hard mask on a silicon substrate to form a silicon wafer base material; forming an opening on the hard mask by photolithography or etching; carrying out an oxidation reaction on a portion of the silicon substrate exposed by the opening, forming an oxide layer having a bottom embedded in the silicon substrate and a top protruding and exposed outside the hard mask by oxidizing the silicon substrate; and polishing the oxide layer by chemical mechanical planarization. In the present disclosure, the surface formed by the oxide layer and the hard mask flat is flat, without a recess even in the case of large structures, thereby precisely controlling a shape and a depth of the cavity in accordance with an oxidation rate on a silicon substrate.
    Type: Application
    Filed: September 6, 2019
    Publication date: November 12, 2020
    Inventors: Lieng Loo, Wooicheang Goh, Kahkeen Lai
  • Patent number: 10818511
    Abstract: The disclosure provides a plane polishing method and a processing method of the silicon wafer. The plane polishing method includes steps of: depositing a hard mask on a silicon substrate to form a silicon wafer base material; forming an opening on the hard mask by photolithography or etching; carrying out an oxidation reaction on a portion of the silicon substrate exposed by the opening, forming an oxide layer having a bottom embedded in the silicon substrate and a top protruding and exposed outside the hard mask by oxidizing the silicon substrate; and polishing the oxide layer by chemical mechanical planarization. In the present disclosure, the surface formed by the oxide layer and the hard mask flat is flat, without a recess even in the case of large structures, thereby precisely controlling a shape and a depth of the cavity in accordance with an oxidation rate on a silicon substrate.
    Type: Grant
    Filed: September 6, 2019
    Date of Patent: October 27, 2020
    Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.
    Inventors: Lieng Loo, Wooicheang Goh, Kahkeen Lai
  • Publication number: 20200048080
    Abstract: The present invention provides a manufacturing method for MEMS structure. The method includes steps of: S1: providing a substrate, including a structural layer and a silicon-based layer overlapped with the structural layer; S2: carrying out a main etching process for etching out a cavity hole from an end of the silicon-based layer, which is far away from the structural layer, in a direction toward the structural layer until the cavity hole contacts the structural layer; and S3: carrying out an over-etching process for deepening the cavity hole and control an included angle ? between a side wall of the cavity hole and the structural layer to be larger than 10° but smaller than 90°. The invention also provides a MEMS structural and a MEMS microphone manufactured by the method.
    Type: Application
    Filed: March 25, 2019
    Publication date: February 13, 2020
    Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai
  • Publication number: 20190337799
    Abstract: The present disclosure provides a method for processing a conductive structure. The method includes the following steps of: forming on a first surface a groove concave from the first surface towards a second surface by means of dry etching; extending the groove from the second surface to form a via through a silicon base; and processing a conductive structure within the via. The method can be applied to a silicon base having a thickness larger than 300 ?m. It breaks the limit on thickness that can be processed in the related art and is capable of providing electrical connectivity on both sides of a silicon base. The method is simple and highly reliable, has high processing efficiency and is applicable to mechanized production.
    Type: Application
    Filed: January 7, 2019
    Publication date: November 7, 2019
    Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai, Kianheng Goh