Method of tailoring conformality of Si-containing film
AssigneeASM Japan K.K.
InventorsShigeyuki Onizawa, Woo-Jin Lee, Hideaki Fukuda, Kunitoshi Namba
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Abstract
A method of tailoring conformality of a film deposited on a patterned surface includes: (I) depositing a film by PEALD or pulsed PECVD on the patterned surface; (II) etching the film, wherein the etching is conducted in a pulse or pulses, wherein a ratio of an etching rate of the film on a top surface and that of the film on side walls of the patterns is controlled as a function of the etching pulse duration and the number of etching pulses to increase a conformality of the film; and (III) repeating (I) and (II) to satisfy a target film thickness.
Claims14
A method of forming a Si-containing film on a patterned surface of a substrate, comprising:
- (i) depositing a Si-containing sub-layer on the patterned surface by pulsed plasma enhanced chemical vapor deposition (PPECVD) or plasma enhanced atomic layer deposition (PEALD), wherein a thickness of the sub-layer is T1 at a top surface of the patterned surface, referred to as top thickness, and S1 at a side wall of the patterned surface, referred to as side thickness, wherein S1/T1 is less than one;
- (ii) etching the sub-layer by reducing T1 more than S1 to obtain a second top thickness T2 and a second side thickness S2, wherein S2/T2 is closer to one than is S1/T1, wherein the etching is conducted by pulsing:
- step (a) of exposing the sub-layer to an excited etching gas and step (b) of purging the excited etching gas therefrom while no excited etching gas is supplied, said excited etching gas being produced by a remote plasma unit and introduced in pulses into a reaction chamber where the substrate is placed, each pulse having a. duration of step (a) of 1 to 10 seconds and being separated by step (b) whose duration is equal to or longer than the duration of step (a);
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- (iii) repeating steps (i) and (ii) multiple times to increase the top thickness and the side thickness, thereby forming a Si-containing film composed of laminated multiple sub-layers on the patterned surface.
A method of tailoring conformality of a Si-containing film deposited by pulsed plasma enhanced chemical vapor deposition (PPECVD) or plasma enhanced atomic layer deposition (PEALD), comprising:
- (i) setting a target conformality, S/T, of a target film deposited on a patterned surface of a substrate, where S denotes a thickness of the target film at a side wall of the patterned surface, and T denotes a thickness of the target film at a top surface of the patterned surface;
- (ii) introducing during a first period a Si-containing deposition gas in pulses into a reaction area where the substrate with the patterned surface is placed, wherein a pulse of introducing the deposition gas is repeated multiple times, while no etching gas is introduced into the reaction area during the first period;
- (iii) applying RF power to the reaction area at least when the deposition gas is not introduced during the first period, thereby depositing a film on the patterned surface of the substrate, wherein a thickness of the film is Ti at a top surface of the patterned surface and S1 at a side wall of the patterned surface;
- (iv) discontinuing the introduction of the deposition gas and the application of RF power and exposing the film to excited etching gas during a second period, wherein the exposure of the excited etching gas to the film is conducted by pulsing:
- step (a) of exposing the film to the excited etching gas and step (b) of purging the excited etching gas therefrom while no excited etching gas is supplied during the second period said excited etching gas being introduced into the reaction area in pulses from a remote plasma unit, each pulse having a duration of step (a) of 1 to 10 seconds and being separated by step (b) whose duration is equal to or longer than the duration of step (a), wherein no Si-containing deposition gas is introduced during the second period, thereby reducing the thickness of the film to T2 at the top surface of the patterned surface and S2 at the side wall of the patterned surface, wherein S2/T2 is closer to 1than is S1/T1;
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- (v) if S2/T2 is not satisfactorily close to S/T, pulsing the exposure of the excited etching gas to the film, shortening a time period of each pulse, and increasing the number of pulses relative to those in immediately previous step (iv), followed by conducting steps (ii) to (iv).
Dependencies are inferred from the claim text.