Method for forming capacitor of semiconductor device using high temperature oxidation

• US 6,248,640 B1
• Filed: 06/25/1999
• Issued: 06/19/2001
• Est. Priority Date: 06/25/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Nam, Sang-don
• Primary Examiner(s): Chaudhari, Chandra
• Assistant Examiner(s): Huynh, Yennhu B.
• Application Number:
  US09/344,585
• Time in Patent Office: 725 Days
• Field of Search: 438/396, 438/399, 438/253, 438/256, 438/649, 438/682
• US Class Current: 438/396
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02323 introduction of oxygen
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence
• CPC Class Codes: H01L 21/3165 formed by oxidation H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 28/56 the dielectric comprising two or more layers, e.g. comprising buffer layers, seed layers, gradient layers
• CPC Class Codes: H01L 28/60 Electrodes

Abstract

A method of forming a capacitor of a semiconductor device which can prevent disconnection between lower electrodes by blanket-depositing a second conductive film for silicidation on a semiconductor substrate and forming an oxide of the second conductive film such as titanium dioxide (TiO₂) on an interlayer dielectric using high temperature oxidation, before depositing a dielectric film, and which can obtain a high capacitance by forming both a silicide layer including the second conductive film, and the oxide of the second conductive film such as titanium dioxide (TiO₂) having a high dielectric constant, on a lower electrode, and using the silicide layer and oxide as the dielectric film.

Claims

1. A method of forming a capacitor of a semiconductor device using high-temperature oxidation, comprising the steps of:

forming a capacitor lower electrode pattern of a first polysilicon film on a semiconductor substrate on which an interlayer dielectric is formed;

depositing a second conductive film on the entire surface of the semiconductor substrate on which the capacitor lower electrode is formed;

forming silicide mixed with the second conductive film and an oxide of the second conductive film on the capacitor lower electrode pattern by oxidizing the semiconductor substrate on which the second conductive film is formed, at a high temperature, and forming only the oxide of the second conductive film on the interlayer dielectric;

depositing a dielectric film on the semiconductor substrate on which the high temperature oxidation was performed; and

forming an upper electrode of a third conductive film on the semiconductor substrate on which the dielectric film has been deposited.

2. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, wherein the first polysilicon film is formed of polysilicon doped with impurities.

3. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, wherein the second conductive film is formed of one material selected from the group consisting of titanium (Ti), tungsten (W), tantalum (Ta), molybdenum (Mo), platinum (Pt), cobalt (Co), palladium (Pd), nickel (Ni) and hafnium (Hf).

4. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, wherein in the high temperature oxidation, the semiconductor substrate is introduced into a chamber of a rapid thermal processing (RTP) apparatus, and rapid thermal oxidation (RTO) is performed on the semiconductor substrate for between 30 seconds and 5 minutes, under an oxygen atmosphere, at a temperature of 650 degree C. to 850 degree C.

5. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, wherein in the high temperature oxidation, the semiconductor substrate is introduced into a furnace and dry-oxidized for between 5 minutes and one hour, under an oxygen atmosphere, at a temperature of 650 degree C. to 850 degree C.

6. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, wherein in the high temperature oxidation, the semiconductor substrate is introduced into a furnace and wet-oxidized for between 5 minutes and one hour, at a temperature of 600 degree C. to 800 degree C.

7. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, wherein the dielectric film is a single film or a composite film including at least one film selected from the group consisting of an oxide film, a nitride film, and ditantalum pentoxide (Ta₂O₅).

8. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, further comprising the step of post-processing the dielectric film after the step of depositing the dielectric film.

9. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 8, wherein ultraviolet ozone (UV-O₃) processing or oxidation is used for the post-processing.

10. The method of forming a capacitor of a semiconductor device using high-temperature oxidation as claimed in claim 1, wherein the third conductive film is formed of polysilicon doped with impurities, or a metal.