US 12,148,625 B2
Methods to prevent surface charge induced cd-dependent etching of material formed within features on a patterned substrate
Shan Hu, Albany, NY (US); Henan Zhang, Albany, NY (US); Sangita Kumari, Albany, NY (US); Peter Delia, Albany, NY (US); and Robert Clark, Fremont, CA (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Sep. 16, 2022, as Appl. No. 17/946,609.
Prior Publication US 2024/0096638 A1, Mar. 21, 2024
Int. Cl. H01L 21/311 (2006.01); H01L 21/306 (2006.01); H01L 21/3213 (2006.01)
CPC H01L 21/31111 (2013.01) [H01L 21/30604 (2013.01); H01L 21/32134 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A method of etching, the method comprising:
providing a patterned substrate having a plurality of features, wherein a critical dimension (CD) of the plurality of features is small compared to more planar areas of the patterned substrate;
forming a liner layer within the plurality of features before the plurality of features is filled with a material to be etched;
depositing the material to be etched within the plurality of features and on the more planar areas of the patterned substrate; and
exposing the patterned substrate to an etch solution to etch the material deposited within the plurality of features and on the more planar areas of the patterned substrate;
wherein when exposed to the etch solution, the liner layer prevents surface charge induced CD-dependent etching of the material deposited within the plurality of features and enables the etch solution to etch the material deposited within the plurality of features and across the more planar areas of the patterned substrate at a uniform etch rate.
 
14. A method of etching, the method comprising:
providing a patterned substrate having a plurality of features, wherein a critical dimension (CD) of the plurality of features is small compared to more planar areas of the patterned substrate;
forming a liner layer within the plurality of features before the plurality of features is filled with a material to be etched;
depositing the material to be etched within the plurality of features and on the more planar areas of the patterned substrate; and
exposing the patterned substrate to an etch solution to etch the material deposited within the plurality of features and on the more planar areas of the patterned substrate, wherein the etch solution comprises a pH value;
wherein when exposed to the etch solution, the liner layer exhibits a neutral surface charge substantially equal to 0 mV at the pH value of the etch solution, and wherein the neutral surface charge prevents surface charge induced CD-dependent etching of the material deposited within the plurality of features and enables the etch solution to etch the material within the plurality of features and across the more planar areas of the patterned substrate at a uniform etch rate.