US 12,002,683 B2
Lateral etching of silicon
Hamed Hajibabaeinajafabadi, Albany, NY (US); Pingshan Luan, Albany, NY (US); Aelan Mosden, Albany, NY (US); and Sergey Voronin, Albany, NY (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Apr. 5, 2022, as Appl. No. 17/713,723.
Prior Publication US 2023/0317465 A1, Oct. 5, 2023
Int. Cl. H01L 21/3213 (2006.01); H01L 21/02 (2006.01); H01L 21/311 (2006.01); H01L 29/40 (2006.01); H01L 29/66 (2006.01)
CPC H01L 21/31116 (2013.01) [H01L 21/02532 (2013.01); H01L 29/66439 (2013.01); H01L 29/66742 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of processing a substrate, the method comprising:
positioning a substrate in a plasma processing chamber, the substrate comprising a layer stack of alternating layers of silicon (Si) layers and silicon-germanium (SiGe) layers, the substrate comprising a recess that exposes sidewalls of the Si layers and sidewalls of the SiGe layers;
flowing a first process gas into the plasma processing chamber;
while flowing the first process gas, pulsing a second process gas into the plasma processing chamber at a pulsing frequency, the second process gas being different from the first process gas;
while flowing the first process gas and pulsing the second process gas, applying power to a source electrode and a bias electrode of the plasma processing chamber to generate a plasma in the plasma processing chamber; and
exposing the substrate to the plasma to laterally etch a portion of the Si layers selectively to the SiGe layers and form indents between the SiGe layers.