Semiconductor device and manufacturing method thereof

• US 6,335,241 B1
• Filed: 08/05/1999
• Issued: 01/01/2002
• Est. Priority Date: 08/07/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Suguro, Kyoichi, Hieda, Katsuhiko, Yamazaki, Soichi, Eguchi, Kazuhiro
• Primary Examiner(s): Faberry, Wael
• Assistant Examiner(s): TOLEDO, FERNANDO L
• Application Number:
  US09/369,174
• Time in Patent Office: 880 Days
• Field of Search: 438/210, 438/239, 438/244, 438/245, 438/250, 438/253, 438/255, 438/396, 438/397, 438/241, 438/387, 438/381, 438/637, 438/638, 257/302, 257/303, 257/304, 257/305, 257/306, 257/307, 257/308, 257/309, 257/310
• US Class Current: 438/253
• CPC Class Codes: H01L 28/91 made by depositing layers, e.g. by depositing alternating conductive and insulating layers
• CPC Class Codes: H10B 12/0335 Making a connection between the transistor and the capacitor, e.g. plug
• CPC Class Codes: H10B 12/09 with simultaneous manufacture of the peripheral circuit region and memory cells
• CPC Class Codes: H10B 12/485 Bit line contacts

Abstract

A semiconductor device with a charge holding capacitor comprises a lower electrode connected via a plug to one of the source and drain of an MIS transistor, a capacitor insulating film formed the lower electrode, an upper electrode formed on the capacitor insulating film. The lower electrode includes a first constituting portion that is embedded in a hole in which the plug has been embedded and so formed that it self-aligns with the plug and a second constituting portion which is formed on the first constituting portion and on regions outside the fist constituting portion and whose cross section is larger than that of the first constituting portion. The first constituting portion and the second constituting portion are formed integrally by a continues film.

Claims

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

the step of forming an insulating film on a substrate in which an MIS transistor has been formed;

the step of removing part of said insulating film to make a hole whose side faces widen gradually as they go downward;

the step of embedding in said hole a conductive film that is connected to one of a source and a drain of the MIS transistor and is to make a lower electrode of a capacitor;

the step of removing said insulating film to expose at least part of the side faces of said conducting film;

the step of forming a capacitor insulating film on the top face of and the exposed side faces of said conducting film; and

the step of forming an upper electrode of the capacitor on said capacitor insulating film.

2. The method according to claim 1, wherein the step of removing part of said insulating film to make a hole whose side faces widen gradually as they go downward includes:

the step of making a first hole whose side faces widen gradually as they go downward by removing part of said insulating film; and

the step of enlarging said first hole by etching said insulating film, thereby transforming said first hole into a second hole.

3. A method of manufacturing a semiconductor device, comprising:

the step of forming a first insulating film on a substrate in which an MIS transistor has been formed and a second insulating film on said first insulating film;

the step of removing part of said first and second insulating films to make a first hole;

the step of enlarging an upper portion of said first hole by etching said second insulating film with reference to said first insulating film, thereby transforming said first hole into a second hole;

the step of embedding in said second hole a conductive film that is connected to one of a source and a drain of said MIS transistor and is to make a lower electrode of a capacitor;

the step of removing said second insulating film to expose at least part of the side faces of said conducting film;

the step of forming a capacitor insulating film on the top face of and the exposed side faces of said conducting film; and

the step of forming an upper electrode of the capacitor on said capacitor insulating film.

4. A method of manufacturing a semiconductor device, comprising:

the step of forming an insulating film with a hole on a substrate in which an MIS transistor has been formed;

the step of forming in said hole a plug connected to one of a source and a drain of said MIS transistor in such a manner that a top face of said plug is positioned between a top and a bottom of said hole;

the step of forming a first conducting film on said plug in said hole;

the step of exposing at least part of the side faces of said first conducting film by removing part of said insulating film;

the step of forming a second conducting film on the exposed side faces of or the exposed side faces and top face of said first conducting film;

the step of forming a capacitor insulating film on a lower electrode of a capacitor composed of said first and second conducting films; and

the step of forming an upper electrode of the capacitor on said capacitor insulating film.

5. A method of manufacturing a semiconductor device, comprising:

the step of forming a first insulating film on a substrate in which an MIS transistor has been formed, and a second insulating film on said first insulating film;

the step of removing part of said first and second insulating films to make a first hole;

the step of forming in said first hole a plug connected to one of a source and a drain of said MIS transistor in such a manner that the top face of said plug is positioned at a lower level than a top of said first insulating film and at a higher level than a bottom of said first insulating film;

the step of enlarging an upper portion of said first hole by etching said second insulating film with reference to said first insulating film, thereby transforming said first hole into a second hole;

the step of embedding a conducting film in said second hole, thereby connecting said conducting film to said plug;

the step of exposing at least part of the side faces of said conducting film by removing said second insulating film,

the step of forming a capacitor insulting film on the lower electrode of a capacitor composed of said conducting film; and

the step of forming the upper electrode of the capacitor on said capacitor insulating film.