Method of manufacturing semiconductor device with offset sidewall structure

• US 20030059983A1
• Filed: 08/06/2002
• Published: 03/27/2003
• Est. Priority Date: 09/21/2001
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Oda, Hidekazu, Ota, Kazunobu, Sayama, Hirokazu
• Granted Patent: US 7,220,637 B2
• Time in Patent Office: Days
• US Class Current: 438/128
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/265 producing ion implantation
• CPC Class Codes: H01L 21/28017 the insulator being formed after the semiconductor body, the semiconductor being silicon
• CPC Class Codes: H01L 21/28158 Making the insulator
• CPC Class Codes: H01L 21/823814 with a particular manufacturing method of the source or drain structures, e.g. specific source or drain implants or silicided source or drain structures or raised source or drain structures
• CPC Class Codes: H01L 21/823857 with a particular manufacturing method of the gate insulating layers, e.g. different gate insulating layer thicknesses, particular gate insulator materials or particular gate insulator implants
• CPC Class Codes: H01L 21/823864 with a particular manufacturing method of the gate sidewall spacers, e.g. double spacers, particular spacer material or shape
• CPC Class Codes: H01L 27/092 complementary MIS field-effect transistors
• CPC Class Codes: H01L 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material

Abstract

A method of manufacturing a semiconductor device with NMOS and PMOS transistors is provided. The semiconductor device can lessen a short channel effect, can reduce gate-drain current leakage, and can reduce parasitic capacitance due to gate overlaps, thereby inhibiting a reduction in the operating speed of circuits. An N-type impurity such as arsenic is ion implanted to a relatively low concentration in the surface of a silicon substrate (1) in a low-voltage NMOS region (LNR) thereby to form extension layers (61). Then, a silicon oxide film (OX2) is formed to cover the whole surface of the silicon substrate (1). The silicon oxide film (OX2) on the side surfaces of gate electrodes (51-54) is used as an offset sidewall. Then, boron is ion implanted to a relatively low concentration in the surface of the silicon substrate (1) in a low-voltage PMOS region (LPR) thereby to form P-type impurity layers (621) later to be extension layers (62).

Claims

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

(a) sectioning a major surface of a semiconductor substrate into at least a first NMOS region for forming a first NMOS transistor and a first PMOS region for forming a first PMOS transistor;

(b) selectively forming a first gate insulating film in both said first NMOS region and said first PMOS region to form a first gate electrode and a second gate electrode on said first gate insulating film in said first NMOS region and said first PMOS region, respectively; and

(c) ion implanting an N-type impurity using at least said first gate electrode as part of an implant mask to form a pair of first extension layers in the surface of said semiconductor substrate outside a side surface of said first gate electrode, and ion implanting a P-type impurity using at least said second gate electrode as part of an implant mask to form a pair of second extension layers in the surface of said semiconductor substrate outside a side surface of said second gate electrode,

said step (c) including the step of;

(c-1) forming first ion-implanted layers by ion implantation of said N-type impurity and second ion-implanted layers by ion implantation of said P-type impurity so that a spacing between said second ion-implanted layers is wider than a spacing between said first ion-implanted layers.

2. The method according to claim 1, wherein

said step (c-1) includes the steps of:

(c-1-1) forming a first offset sidewall on side surfaces of said first and second gate electrodes;

(c-1-2) ion implanting said N-type impurity into said first NMOS region using said first gate electrode and said first offset sidewall as implant masks to form said first ion-implanted layers in the surface of said semiconductor substrate outside the side surface of said first gate electrode;

(c-1-3) forming a second offset sidewall on a side surface of said first offset sidewall; and

(c-1-4) ion implanting said P-type impurity into said first PMOS region using said second gate electrode and said first and second offset sidewalls as implant masks to form said second ion-implanted layers in the surface of said semiconductor substrate outside the side surface of said second gate electrode.

3. The method according to claim 2, wherein

said step (a) includes the step of further sectioning said major surface of said semiconductor substrate into a second NMOS region for forming a second NMOS transistor with a higher operating voltage than said first NMOS transistor and a second PMOS region for forming a second PMOS transistor with a higher operating voltage than said first PMOS transistor, and

said step (b) includes the step of:

selectively forming a second gate insulating film greater in thickness than said first gate insulating film on both said second NMOS region and said second PMOS region, to form a third gate electrode and a fourth gate electrode on said second gate insulating film in said second NMOS region and said second PMOS region, respectively,

the method further comprising the steps, performed prior to said step (c), of;

forming an offset sidewall on side surfaces of said third and fourth gate electrodes;

ion implanting an N-type impurity into said second NMOS region using said third gate electrode and said offset sidewall as implant masks to form a pair of third extension layers in the surface of said semiconductor substrate outside the side surface of said third gate electrode; and

ion implanting a P-type impurity into said second PMOS region using said fourth gate electrode and said offset sidewall as implant masks to form a pair of fourth extension layers in the surface of said semiconductor substrate outside the side surface of said fourth gate electrode.

4. The method according to claim 3, wherein

said step (c-1-1) includes the step of forming a first insulation film on the whole surface of said semiconductor substrate to cover said offset sidewall and forming said first offset sidewall by increasing the thickness of said offset sidewall.

5. The method according to claim 2, further comprising the steps of:

(d) forming a first sidewall insulating film on a side surface of said second offset sidewall in at least said first NMOS region and said first PMOS region;

(e) ion implanting an N-type impurity into at least said first NMOS region using said first gate electrode, said first and second offset sidewalls and said first sidewall insulating film as implant masks, to form first source/drain layers in the surface of said semiconductor substrate outside the side surface of said first gate electrode;

(f) forming a second sidewall insulating film on a side surface of said first sidewall insulating film; and

(g) ion implanting a P-type impurity into at least said first PMOS region using said second gate electrode, said first and second offset sidewalls and said first and second sidewall insulating films as implant masks, to form second source/drain layers in the surface of said semiconductor substrate outside the side surface of said second gate electrode,

said steps (d) and (e) being performed after said step (c),

said steps (f) and (g) being performed after said step (e).

6. The method according to claim 2, wherein

said step (c-1-1) includes the step of forming a first insulation film on the whole surface of said semiconductor substrate and, by removing said first insulation film on the surface of said semiconductor substrate by anisotropic etching, leaving said first insulation film on the side surfaces of said first and second gate electrodes to form said first offset sidewall,

said step (c-1-3) includes the step of forming a second insulation film on the whole surface of said semiconductor substrate, said second insulation film formed on the side surface of said first offset sidewall forming said second offset sidewall, and

said step (c-1-4) includes the step of ion implanting said P-type impurity with said second insulation film left in the surface of said semiconductor substrate.