US 12,230,636 B2
Apparatus and circuits with dual threshold voltage transistors and methods of fabricating the same
Chan-Hong Chern, Palo Alto, CA (US)
Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on May 16, 2023, as Appl. No. 18/198,195.
Application 18/198,195 is a continuation of application No. 16/575,808, filed on Sep. 19, 2019, granted, now 11,682,676.
Claims priority of provisional application 62/753,484, filed on Oct. 31, 2018.
Prior Publication US 2023/0290782 A1, Sep. 14, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 27/095 (2006.01); H01L 21/02 (2006.01); H01L 21/8252 (2006.01); H01L 29/20 (2006.01); H01L 29/205 (2006.01); H01L 29/423 (2006.01); H01L 29/49 (2006.01); H01L 29/66 (2006.01); H01L 29/778 (2006.01); H03K 17/16 (2006.01)
CPC H01L 27/095 (2013.01) [H01L 21/0254 (2013.01); H01L 21/8252 (2013.01); H01L 29/2003 (2013.01); H01L 29/205 (2013.01); H01L 29/4958 (2013.01); H01L 29/66462 (2013.01); H01L 29/7787 (2013.01); H03K 17/161 (2013.01); H01L 21/02381 (2013.01); H01L 29/42316 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A semiconductor structure, comprising:
a substrate;
a first layer comprising a first III-V semiconductor material formed over the substrate;
a polarization modulation layer disposed above the first layer;
a passivation layer disposed at least partially on the polarization modulation layer;
a first transistor formed over the substrate, wherein the first transistor comprises a first gate structure comprising a first material, a first source region and a first drain region; and
a second transistor formed next to the first transistor over the substrate, wherein the second transistor comprises a second gate structure comprising a second material, a second source region and a second drain region, wherein:
the first gate structure is disposed partially on the polarization modulation layer and partially on the passivation layer;
the second gate structure is disposed partially on the polarization modulation layer and partially on the passivation layer; and
the first material has a different work function than that of the second material.