METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

• US 20150340281A1
• Filed: 05/21/2015
• Published: 11/26/2015
• Est. Priority Date: 05/23/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Mong-sup, LEE, Sang-jun, SON, Yoon-ho
• Granted Patent: US 9,570,316 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/31111 by chemical means
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/764 Air gaps H01L21/76264 takes precedence
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 21/76895 Local interconnects; Local pads, as exemplified by patent document EP0896365
• CPC Class Codes: H01L 21/76897 Formation of self-aligned vias or contact plugs, i.e. involving a lithographically uncritical step self-aligned silicidation on field effect transistors H01L29/665
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: H10B 12/0335 Making a connection between the transistor and the capacitor, e.g. plug
• CPC Class Codes: H10B 12/482 Bit lines

Abstract

A method of manufacturing a semiconductor device includes forming a first conductive structure on a substrate, forming an insulation layer on a sidewall of the first conductive structure, forming a second conductive structure a distance apart from the first conductive structure with the insulation layer therebetween, first removing a portion of the insulation layer by performing a first dry cleaning operation, second removing a reactant product used in the first dry cleaning operation or a first byproduct generated as a result of the first dry cleaning operation by performing a first purge operation, and third removing at least a portion of the remaining insulation layer by performing a second dry cleaning operation to form an air gap between the first and second conductive structures.

Claims

1. A method of manufacturing a semiconductor device, the method comprising:

forming a first conductive structure on a substrate;

forming an insulation layer on a sidewall of the first conductive structure;

forming a second conductive structure a distance apart from the first conductive structure with the insulation layer therebetween;

first removing a portion of the insulation layer by performing a first dry cleaning operation;

second removing a reactant product used in the first dry cleaning operation or a first byproduct generated as a result of the first dry cleaning operation by performing a first purge operation; and

third removing at least a portion or all of the remaining insulation layer by performing a second dry cleaning operation to form an air gap between the first and second conductive structures.

2. The method of claim 1, wherein the third removing removes only a portion of the remaining insulating layer in the second dry cleaning operation, and the second dry cleaning operation and the first purge operation are repeatedly performed until the air gap has at least one of a target width and a target depth.

3. The method of claim 2, wherein the repeatedly performing the second dry cleaning operation and the first purge operation includes repeatedly supplying an etching gas and stopping the supply of the etching gas to sublimate a second byproduct generated as a result of the second dry cleaning operation and the first purge operation.

4. The method of claim 2, further comprising:

determining whether removal of a second byproduct is required after the second dry cleaning operation; and

performing a second purge operation at a temperature higher than a temperature of the second dry cleaning operation to sublimate the second byproduct if removal of the second byproduct is required.

5. The method of claim 1, wherein a temperature of the first purge operation is higher than a temperature of the second dry cleaning operation.

6. The method of claim 1, wherein the second removing performs the first purge operation while supplying an inert gas or at a pressure adjusted to be lower than a pressure of the first dry cleaning operation and the second dry cleaning operation.

7. The method of claim 1, wherein the third removing removes only a portion of the remaining insulation layer in the second dry cleaning operation such that the remaining portion of the insulation layer defines the air gap between the first and second conductive structures.

8. The method of claim 1, wherein at least one of the forming a first conductive structure and forming a second conductive structure forms a structure in which different conductive materials are bonded.

9. The method of claim 1, wherein the forming a first conductive structure forms a bit line, and the forming a second conductive structure forms a buried contact, further comprising:

forming a landing pad pattern to expose the buried contact and a portion of the remaining insulation layer after the forming a buried contact,

wherein the first dry cleaning operation and the second dry cleaning operation are performed after the forming a landing pad pattern.

10. The method of claim 1, wherein the first removing and the third removing uses a plasma-less gas.

11. The method of claim 1, wherein the first removing and the third removing uses a gas including at least one of NH₃, HF, NF₃, H₂, and IPA (isopropyl alcohol).

12. The method of claim 1, wherein the first removing and the third removing uses an inert gas.

13. The method of claim 1, further comprising:

removing a portion of the insulation layer by performing a wet cleaning operation before the first removing.

14. The method of claim 13, wherein

at least one of the forming a first conductive structure and the forming a second conductive structure forms a structure in which different conductive materials are stacked, and

the removing a portion of the insulation layer by performing a wet cleaning operation forms a remaining insulation layer having an upper surface that is at a level higher than a level of bonding interfaces of the different conductive materials.

15. A method of manufacturing a semiconductor device, the method comprising:

forming a device isolation layer defining an active area in a substrate;

forming a conductive structure connected to the active area;

forming an insulation layer connected to the device isolation layer on a sidewall of the conductive structure;

removing the insulation layer by repeatedly performing a first dry cleaning operation and a purge operation to form a first air gap; and

removing the device isolation layer that is fluidly connected to the first air gap by repeatedly performing a second dry cleaning operation and a purge operation to form a second air gap.

16. A method of manufacturing a semiconductor device, the method comprising:

forming a structure on a substrate, the structure including,

a bit line on the substrate, and

an insulation layer on a sidewall of the bit line; and

removing at least a portion of the insulation layer by performing at least two cycles of a dry cleaning operation and a purge operation to form an air gap.

17. The method of claim 16, wherein the removing includes performing the cycles of a dry cleaning operation and purge operation until the air gap has at least one of a target width and a target depth.

18. The method of claim 16, wherein the removing removes the entire insulating layer.

19. The method of claim 16, wherein the removing removes at least the portion of the insulation layer using a gas including at least one of a plasma-less gas, an inert gas, NH₃, HF, NF₃, H₂, and IPA (isopropyl alcohol).

20. The method of claim 16, wherein the removing performs the dry cleaning operation at a temperature of about 100°

C. to about 300°

C. and at a pressure of about 0.00001 atm to about 0.3 atm.