Abstract: The present disclosure generally relate to thin films incorporating high aspect ratio feature definitions and methods for forming the same. As gate height increases, 3D NAND gate stacks are subject to higher aspect ratio etching. Due to the current limitations of etching techniques, the vertical etch profile typically tapers as the depth into the gate stack increases. The inventors have devised a unique deposition scheme that compensates for etch performance degradation in deep trenches by a novel plasma-enhanced chemical vapor deposition (PECVD) film deposition method. The inventors have found that by grading various properties (e.g., refractive index, stress of the film, dopant concentration in the film) of the as-deposited films (e.g., silicon nitride) a more uniform etch profile can be achieved by compensating for variations in both dry and wet etch rates.

Abstract: The present disclosure generally relate to thin films incorporating high aspect ratio feature definitions and methods for forming the same. As gate height increases, 3D NAND gate stacks are subject to higher aspect ratio etching. Due to the current limitations of etching techniques, the vertical etch profile typically tapers as the depth into the gate stack increases. The inventors have devised a unique deposition scheme that compensates for etch performance degradation in deep trenches by a novel plasma-enhanced chemical vapor deposition (PECVD) film deposition method. The inventors have found that by grading various properties (e.g., refractive index, stress of the film, dopant concentration in the film) of the as-deposited films (e.g., silicon nitride) a more uniform etch profile can be achieved by compensating for variations in both dry and wet etch rates.

Abstract: A method for forming a high aspect ratio feature is disclosed. The method includes depositing one or more silicon oxide/silicon nitride containing stacks on a substrate by depositing a first film layer on the substrate from a first plasma and depositing a second film layer having a refractive index on the first film layer from a second plasma. A predetermined number of first film layers and second film layers are deposited on the substrate. The first film layer and the second film layer are either a silicon oxide layer or a silicon nitride layer and the first film layer is different from the second film layer. The method further includes depositing a third film layer from a third plasma and depositing a fourth film layer on the third film layer from a fourth plasma. The fourth film layer has a refractive index greater than the first refractive index.

Abstract: Implementations of the present disclosure generally relate to thin films incorporating high aspect ratio feature definitions and methods for forming the same. As gate height increases, 3D NAND gate stacks are subject to higher aspect ratio etching. Due to the current limitations of etching techniques, the vertical etch profile typically tapers as the depth into the gate stack increases. The inventors have devised a unique deposition scheme that compensates for etch performance degradation in deep trenches by a novel plasma-enhanced chemical vapor deposition (PECVD) film deposition method. The inventors have found that by grading various properties (e.g., refractive index, stress of the film, dopant concentration in the film) of the as-deposited films (e.g., silicon nitride) a more uniform etch profile can be achieved by compensating for variations in both dry and wet etch rates.