US 12,074,036 B2
Multi-layered polysilicon and oxygen-doped polysilicon design for RF SOI trap-rich poly layer
Yu-Hung Cheng, Tainan (TW); Cheng-Ta Wu, Shueishang Township (TW); Chen-Hao Chiang, Jhongli (TW); Alexander Kalnitsky, San Francisco, CA (US); Yeur-Luen Tu, Taichung (TW); and Eugene Chen, Taipei (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Nov. 5, 2021, as Appl. No. 17/519,765.
Application 17/519,765 is a division of application No. 16/567,290, filed on Sep. 11, 2019, granted, now 11,171,015.
Prior Publication US 2022/0059364 A1, Feb. 24, 2022
Int. Cl. H01L 21/322 (2006.01); H01L 21/762 (2006.01); H01L 23/66 (2006.01); H01L 29/06 (2006.01); H01L 29/34 (2006.01)
CPC H01L 21/3226 (2013.01) [H01L 21/7624 (2013.01); H01L 23/66 (2013.01); H01L 29/0649 (2013.01); H01L 29/34 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
depositing a first layer of polysilicon over a substrate at a first temperature in a chamber;
introducing oxygen into the chamber to dope a top surface of the first layer of polysilicon at a second temperature less than the first temperature to form a first layer of oxygen-doped polysilicon over the first layer of polysilicon;
depositing a second layer of polysilicon over the first layer of oxygen-doped polysilicon at the first temperature in the chamber;
introducing oxygen into the chamber to dope a top surface of the second layer of polysilicon at the second temperature to form a second layer of oxygen-doped polysilicon over the second layer of polysilicon; and
depositing a capping layer of polysilicon over the second layer of oxygen-doped polysilicon in the chamber at the first temperature;
wherein the first layer of oxygen-doped polysilicon comprises polycrystalline grains and a concentration of oxygen between 10%-20%, wherein the introducing of oxygen into the chamber to dope the top surface of the first layer of polysilicon comprises flowing a premixed gas of helium and oxygen into the chamber at a flow rate of 500 standard cubic centimeters per minute (SCCM), wherein the premixed gas has 0.1-1 atomic percent oxygen, and wherein the first and second layers of polysilicon, the first and second layers of oxygen-doped polysilicon, and the capping layer partially form a semiconductor-on-insulator (SOI) substrate.