Method of selective film deposition for forming fully self-aligned vias

Abstract

A substrate fabrication method for forming a fully self-aligned dielectric window is disclosed. This method can be performed in a batch processing system capable of processing multiple substrates simultaneously. The batch processing system includes a process chamber with a process space surrounding a rotation axis. Each substrate includes a first surface and a second surface, and the method includes selectively forming SiO2 protrusion features on the first surface relative to the second surface.

Description

[Technical Field] Cross-reference to related applications: This application relates to and claims priority to U.S. Provisional Patent Application No. 62 / 588,855, filed November 20, 2017, the entire contents of which are incorporated herein by reference. This application relates to and claims priority to U.S. Provisional Patent Application No. 62 / 685,847, filed June 15, 2018, the entire contents of which are incorporated herein by reference. This invention relates to semiconductor manufacturing processes and semiconductor devices, and more particularly to a selective film deposition method for forming fully self-aligned dielectric windows. [Previous Technology] As device sizes shrink, the complexity of semiconductor device manufacturing increases. The cost of manufacturing semiconductor devices also rises, necessitating cost-effective solutions and innovations. With the fabrication of smaller transistors, producing critical dimensions (CD) or resolutions for patterned features becomes increasingly challenging. At highly miniaturized technology nodes, selective deposition of thin films is a key step in patterning. New deposition methods are needed that can provide selective thin film deposition on surfaces of different materials. [Summary of the Invention] According to one embodiment, a substrate fabrication method is provided. The method includes: (a) disposing a substrate on a plurality of substrate supports in a process chamber, wherein the process chamber includes a process space defined around a pivot axis in the process chamber, each substrate including a first surface and a second surface; and (b) rotating the plurality of substrate supports about the pivot axis. The method further includes: (c) exposing the substrate to a reaction gas including a metal-containing catalyst; (d) exposing the substrate to a cleaning gas that removes an oxide layer together with the metal-containing catalyst thereon from the second surface; and (e) exposing the substrate to a deposition gas containing a silanol gas for a period of time, such that an initial SiO2 film is selectively deposited on the metal-containing catalyst on the first surface, wherein the initial SiO2 film forms a protruding feature adjacent to the second surface. The method further includes: (f) exposing the substrate to the reaction gas to selectively coat the protruding features of the initial SiO2 film with a metal catalyst, but not coating the second surface; and (g) exposing the substrate to the deposition gas containing silanol gas for a period of time, such that an additional SiO2 film is selectively deposited on the metal catalyst on the protruding features of the initial SiO2 film.

Implementation Method

Claims

1. A substrate fabrication method comprising: (a) disposing a substrate on a plurality of substrate supports in a process chamber, wherein the process chamber includes a process space defined about a pivot axis in the process chamber, each of the substrates including a first surface and a second surface; (b) rotating the plurality of substrate supports about the pivot axis; (c) exposing the substrates to a reaction gas containing a metal catalyst; (d) exposing the substrates to a cleaning gas that removes an oxide layer and the metal catalyst on the oxide layer from the second surface; (e) exposing the substrates to a deposition gas containing a silanol gas for a period of time to selectively deposit an initial SiO2 film on the metal catalyst on the first surface, wherein the initial SiO2 film forms a protruding feature adjacent to the second surface; (f) The substrates are exposed to the reaction gas, and the metal-containing catalyst is selectively coated on the protruding features of the initial SiO2 film, but not on the second surface; and (g) the substrates are exposed to the deposition gas containing the silanol gas for a period of time to selectively deposit an additional SiO2 film on the metal-containing catalyst located on the protruding features of the initial SiO2 film.

2. The substrate manufacturing method of claim 1, wherein the first surface comprises a dielectric material and the second surface comprises a metal layer.

3. The substrate manufacturing method of claim 1 further includes: repeating steps (c)-(e) at least once before performing step (f) to increase the thickness of the initial SiO2 film.

4. The substrate manufacturing method of claim 1 further includes: repeating steps (f) and (g) at least once to increase the thickness of the additional SiO2 film on the initial SiO2 film.

5. The substrate manufacturing method of claim 1, wherein steps (f) and (g) are performed without exposing the substrate to a cleaning gas in an intermediate step.

6. The substrate manufacturing method as described in claim 1, wherein the reactant gas comprises aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), or a combination thereof.

7. The substrate manufacturing method as described in claim 1, wherein the reaction gas comprises aluminum trimethylolpropionate (AlMe3).

8. The substrate manufacturing process method of claim 1, wherein the step of exposing the substrate to the deposition gas containing silanol gas is performed at a substrate temperature of about 150°C or lower in the absence of any oxidizing agent and hydrolyzing agent.

9. The substrate manufacturing method of claim 1, wherein the substrate temperature is about 100°C or lower during the exposure steps.

10. The substrate fabrication method of claim 1, wherein the deposition gas is composed of the silanol gas and an inert gas.

11. The substrate manufacturing method of claim 1, wherein the silanol gas is selected from the group consisting of tris(tert-pentoxy) silanol, tris(tert-butoxy) silanol, and bis(tert-butoxy)(isopropoxy) silanol.

12. The substrate fabrication method of claim 1, wherein the initial and additional SiO2 films are deposited on the metal-containing catalyst in a self-limiting manner.

13. The substrate fabrication method of claim 1, wherein the thickness of the initial SiO2 film is about 15 nm or less.

14. The substrate manufacturing method of claim 1, wherein the initial SiO2 thin film is deposited by performing steps (c)-(e) only once in sequence.

15. The substrate fabrication method of claim 1, wherein the thickness of the additional SiO2 thin film is between about 50 nm and about 100 nm.

16. The substrate manufacturing method of claim 1, wherein the cleaning gas comprises an alcohol.

17. The substrate manufacturing method of claim 16, wherein the alcohol comprises isopropanol, methanol or ethanol.

18. The substrate manufacturing method of claim 1, wherein steps (c)-(e) comprise: injecting the reactive gas into a first process space, the first process space being defined by a first angle about the axis of rotation; exposing the first surface and the second surface of each of the substrates to the reactive gas in the first process space during each complete rotation; injecting the cleaning gas into a second process space, the second process space being defined by a second angle about the axis of rotation and separated from the first process space; exposing the first surface and the second surface of each of the substrates to the cleaning gas during each complete rotation; and injecting the deposition gas containing the silanol gas into a third process space, the third process space being defined by a third angle about the axis of rotation and separated from the first and second process spaces.

19. The substrate manufacturing method of claim 18 further includes: repeatedly rotating the substrates through the first, second and third process spaces to expose the first surface and the second surface of each of the substrates to the reaction gas, the cleaning gas and the deposition gas, so as to progressively deposit the initial SiO2 film on each of the substrates.

20. The substrate fabrication method of claim 1, wherein steps (f)-(g) comprise: injecting the reactive gas into a first process space, the first process space being defined by a first angle about the axis of rotation; exposing the first surface of each of the substrates to the reactive gas in the first process space during each complete rotation; injecting the deposition gas containing the silanol gas into a second process space, the second process space being defined by a second angle about the axis of rotation and separated from the first process space; and by repeatedly rotating the substrates through the first and second process spaces, exposing the first surface and the second surface of each of the substrates to the reactive gas and the deposition gas again, so as to progressively deposit the additional SiO2 film on each of the substrates.

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