Lam Research Corporation

Nikhil Dole

Eric A Hudson

Takumi Yanagawa

Merrett Wong

John Patrick Holland

Alexei Marakhtanov

Felix Leib Kozakevich

Bradford J Lyndaker

Ranadeep Bhowmick

George Matamis

Sangheon Lee

Aniruddha Joi

Xiaoqiang Yao

Beibei Jiang

Vikhram Vilasur Swaminathan

Anqi Song

Jay Sheth

A method for performing an etch process on a substrate in a plasma processing system, including: applying source RF power and bias RF power to an electrode; wherein the source RF power and the bias RF power are pulsed signals that together define a plurality of multi-state pulsed RF cycles, each cycle having a first state, second state, and third state; wherein the first state is defined by the source RF power having a first source RF power level and the bias RF power having a first bias RF power level; wherein the second state is defined by the source RF power and the bias RF power having substantially zero power levels; wherein the third state is defined by the source RF power having a second source RF power level less than the first source RF power level, and the bias RF power having a substantially zero power level.

Multi-state RF pulsing to control mask shape and breaking selectivity versus process margin trade-off

A method for performing an etch process on a substrate includes applying a bias signal and a source signal to an electrode of a plasma processing system. The bias signal and the source signal are pulsed RF signals that together define a repeated pulsed RF cycle, wherein each pulsed RF cycle sequentially includes a first state, a second state, a third state, and a fourth state. The power level of the bias signal in the first state is greater than in the third state, which is greater than in the second state, which is greater than in the fourth state. The power level of the source signal in the first state is greater than in the third state, which is greater than in the second state, which is greater than in the fourth state.

Multiple state pulsing for high aspect ratio etch

A method for multi-state pulsing to achieve a balance between bow control and mask selectivity is described. The method includes generating a primary radio frequency (RF) signal. The primary RF signal pulses among three states including a first state, a second state, and a third state. The method further includes generating a secondary RF signal. The secondary RF signal pulses among the three states. During the first state, the primary RF signal has a power level that is greater than a power level of the secondary RF signal. Also, during the second state, the secondary RF signal has a power level that is greater than a power level of the primary RF signal. During the third state, power levels of the primary and secondary RF signals are approximately equal.

Multi-state pulsing for achieving a balance between bow control and mask selectivity

A method of etching features in a stack comprising a dielectric material on a substrate is provided. In a step (a) an etch plasma is generated from an etch gas, exposing the stack to the etch plasma, and partially etching features in the stack. In a step (b) after step (a) an atomic layer deposition process is provided to deposit a protective film on sidewalls. The atomic layer deposition process comprises a plurality of cycles, wherein each cycle comprises exposing the stack to a first reactant gas comprising WF6, wherein the first reactant gas is adsorbed onto the stack and exposing the stack to a plasma formed from a second reactant gas, wherein the plasma formed from the second reactant gas reacts with the adsorbed first reactant gas to form the protective film over the stack. In a step (c) steps (a)-(b) are repeated at least one time.

Method for etching an etch layer

Systems and methods for applying three or more states for achieving a high aspect ratio dielectric etch operation are described. In one of the methods, a middle state is introduced between a high state and a low state. The middle state is applied to both a source radio frequency (RF) generator and a bias radio frequency (RF) generator. During the middle state, RF power is maintained to be between a high amount of RF power associated with the high state and a low amount of RF power associated with the low state to achieve the high aspect ratio dielectric etch.

Three or more states for achieving high aspect ratio dielectric etch

Various embodiments herein relate to methods and apparatus for etching a feature in a substrate. Often, the feature is etched in the context of forming a DRAM device. The feature is etched in dielectric material, which often includes silicon oxide. The feature is etched using chemistry that includes WF. Although WFis commonly used as a deposition gas (e.g., to deposit tungsten-containing film), it can also be used during etching. Advantageously, the inclusion of WFin the etch chemistry can increase the etch rate of the dielectric material, as well as increase the selectivity of the etch. Unexpectedly, these benefits can be realized without any increase in capping.

Method of achieving high selectivity for high aspect ratio dielectric etch

Methods and apparatus for etching a high aspect ratio feature in a stack on a substrate are provided. The feature may be formed in the process of forming a 3D NAND device. Typically, the stack includes alternating layers of material such as silicon oxide and silicon nitride or silicon oxide and polysilicon. WFis provided in the etch chemistry, which substantially reduces or eliminates problematic sidewall notching. Advantageously, this improvement in sidewall notching does not introduce other tradeoffs such as increased bowing, decreased selectivity, increased capping, or decreased etch rate.

Reduction of sidewall notching for high aspect ratio 3D NAND etch

Various embodiments herein relate to methods, apparatus and systems for forming a recessed feature in dielectric material on a substrate. Separate etching and deposition operations are employed in a cyclic manner. Each etching operation partially etches the feature. Each deposition operation forms a protective coating on the sidewalls of the feature to prevent lateral etch of the dielectric material during the etching operations. The protective coating may be deposited using methods that result in substantial preservation of a mask layer on the substrate. The protective coating may be deposited using particular reactants and/or reaction conditions that are unlikely to damage the mask layer. The protective coating may also be deposited using particular reaction mechanisms that result in substantially complete sidewall coating. In some cases the protective coating is deposited using plasma assisted atomic layer deposition, a modified plasma assisted atomic layer deposition, or plasma assisted chemical vapor deposition.

Technique to deposit sidewall passivation for high aspect ratio cylinder etch

Methods, apparatus and systems for forming a recessed feature in dielectric material on a semiconductor substrate are provided. Separate etching and deposition operations are employed in a cyclic manner. Each etching operation partially etches the feature. Each deposition operation forms a protective film on the sidewalls of the feature to prevent lateral etch of the dielectric material during the etching operations. The protective film may be deposited under different conditions (e.g., pressure, duration of reactant delivery, duration of plasma exposure, RF power, and/or RF duty cycle, etc.) in different deposition operations. Such conditions may affect the degree of conformality at which the protective film forms. In various embodiments, one or more protective films may be sub-conformal. In these or other embodiments, one or more other protective films may be conformal.

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Union City, CA, United States of America

Nikhil Dole