US 12,456,646 B2
Methods for forming deep trench isolation structures
Taichou Papo Chen, San Jose, CA (US)
Assigned to Applied Materials Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on May 4, 2022, as Appl. No. 17/736,177.
Claims priority of application No. PCT/US2022/013042 (WO), filed on Jan. 20, 2022.
Prior Publication US 2023/0230872 A1, Jul. 20, 2023
Int. Cl. H01L 21/762 (2006.01); H10F 39/00 (2025.01)
CPC H01L 21/76224 (2013.01) [H10F 39/024 (2025.01); H10F 39/807 (2025.01)] 13 Claims
OG exemplary drawing
 
1. A method of forming a deep trench isolation (DTI) structure in a substrate, comprising:
etching a trench with a high aspect ratio into a substrate material;
repairing surfaces of the trench from damage caused by etching of the trench;
growing an epitaxial layer on surfaces of the trench to form a homogeneous passivation region as part of the substrate material;
doping the epitaxial layer with an additional dopant to engineer a passivation charge region;
performing a charge diffusion process to embed the additional dopant into the substrate material to form an abrupt charge passivation region in the substrate material;
forming a conformal liner layer or a conformal barrier layer directly on the homogeneous passivation region in the trench; and
filling the trench with an optically reflective material after the charge diffusion process is performed.