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).
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Publication number: 20240372528Abstract: 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: ApplicationFiled: May 7, 2023Publication date: November 7, 2024Inventors: DongLiang Pang, LiEng Loo, Kahkeen Lai, Ke Wu, ShirNee Yap
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Publication number: 20240372519Abstract: 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: ApplicationFiled: May 6, 2023Publication date: November 7, 2024Inventors: LiEng Loo, Ke Wu, Kahkeen Lai
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Patent number: 11569791Abstract: 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: GrantFiled: December 29, 2020Date of Patent: January 31, 2023Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
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Patent number: 11482664Abstract: 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: GrantFiled: December 29, 2020Date of Patent: October 25, 2022Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
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Patent number: 11305988Abstract: 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: GrantFiled: September 1, 2020Date of Patent: April 19, 2022Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.Inventors: Wooicheang Goh, Lieng Loo, Kahkeen Lai
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Publication number: 20220063995Abstract: 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: ApplicationFiled: September 1, 2020Publication date: March 3, 2022Inventors: Wooicheang Goh, Lieng Loo, Kahkeen Lai
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Patent number: 11192782Abstract: 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: GrantFiled: September 1, 2020Date of Patent: December 7, 2021Assignee: AAC ACOUSTIC TECHNOLOGIES (SHENZHEN) CO., LTD.Inventors: Wooicheang Goh, Lieng Loo, Kahkeen Lai
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Publication number: 20210336125Abstract: 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: ApplicationFiled: December 29, 2020Publication date: October 28, 2021Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
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Publication number: 20210336596Abstract: 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: ApplicationFiled: December 29, 2020Publication date: October 28, 2021Inventors: Lieng Loo, Kahkeen Lai, Yilei Wu
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Patent number: 11111134Abstract: 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: GrantFiled: January 7, 2019Date of Patent: September 7, 2021Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai, Kianheng Goh
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Patent number: 10947110Abstract: 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: GrantFiled: March 25, 2019Date of Patent: March 16, 2021Assignee: AAC Technologies Pte. Ltd.Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai
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Publication number: 20200357656Abstract: 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: ApplicationFiled: September 6, 2019Publication date: November 12, 2020Inventors: Lieng Loo, Wooicheang Goh, Kahkeen Lai
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Patent number: 10818511Abstract: 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: GrantFiled: September 6, 2019Date of Patent: October 27, 2020Assignee: AAC Acoustic Technologies (Shenzhen) Co., Ltd.Inventors: Lieng Loo, Wooicheang Goh, Kahkeen Lai
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Publication number: 20200048080Abstract: 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: ApplicationFiled: March 25, 2019Publication date: February 13, 2020Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai
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Publication number: 20190337799Abstract: 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: ApplicationFiled: January 7, 2019Publication date: November 7, 2019Inventors: Lieng Loo, Shaoquan Wang, Xiaohui Zhong, Kahkeen Lai, Kianheng Goh