US 12,422,699 B2
Optical modulator and method of forming the same
Chih-Tsung Shih, Hsinchu (TW); Feng Yuan, Hsinchu (TW); Wei-Kang Liu, Taichung (TW); and Yingkit Felix Tsui, Cupertino, CA (US)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD., Hsinchu (TW)
Filed on Aug. 2, 2022, as Appl. No. 17/816,764.
Prior Publication US 2024/0045240 A1, Feb. 8, 2024
Int. Cl. G02B 6/12 (2006.01); G02F 1/025 (2006.01)
CPC G02F 1/025 (2013.01) [G02B 6/12004 (2013.01); G02B 2006/12061 (2013.01); G02B 2006/12123 (2013.01); G02B 2006/12142 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
receiving a silicon substrate;
forming a first doped region and a second doped region in the silicon substrate and laterally spaced by a distance;
forming a third doped region and a fourth doped region on upper portions of the first doped region and the second doped region, respectively, wherein the first doped region or and the second doped region has a first doping concentration between about 5E18 atoms/cm3 and about 5E19 atoms/cm3; and
patterning the silicon substrate to form an optical modulator, the optical modulator comprising:
a first section configured to allow an optical signal to propagate;
a second section and a third section at least formed from the first and second doped regions, respectively, and configured to receive a modulating signal;
a fourth section, including a first height less than that of the first section and the second section and arranged between the first section and the second section, the fourth section being an undoped region; and
a fifth section immediately adjacent to the fourth section, the fifth section including a height less than that of the first section and the second section and different from the first height, the fifth section arranged between the first section and the second section and formed from the first doped region.