RECESSED SALICIDE STRUCTURE TO INTEGRATE A FLASH MEMORY DEVICE WITH A HIGH K, METAL GATE LOGIC DEVICE

• US 20160013198A1
• Filed: 07/14/2014
• Published: 01/14/2016
• Est. Priority Date: 07/14/2014
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Liu, Ming Chyi
• Granted Patent: US 9,349,741 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/28008 Making conductor-insulator-semiconductor electrodes
• CPC Class Codes: H01L 29/40114 the electrodes comprising a conductor-insulator-conductor-insulator-semiconductor structure
• CPC Class Codes: H01L 29/42344 with at least one additional gate, e.g. program gate, erase gate or select gate
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate
• CPC Class Codes: H01L 29/66833 with a charge trapping gate insulator, e.g. MNOS transistors
• CPC Class Codes: H01L 29/792 with charge trapping gate insulator, e.g. MNOS-memory transistors
• CPC Class Codes: H10B 41/35 with a cell select transistor, e.g. NAND
• CPC Class Codes: H10B 43/35 with cell select transistors, e.g. NAND

Abstract

An integrated circuit for an embedded flash memory device is provided. A semiconductor substrate includes a memory region and a logic region adjacent to the memory region. A logic device is arranged over the logic region and includes a metal gate separated from the semiconductor substrate by a material having a dielectric constant exceeding 3.9. A flash memory cell device is arranged over the memory region. The flash memory cell device includes a memory cell gate electrically insulated on opposing sides by corresponding dielectric regions. A silicide contact pad is arranged over a top surface of the memory cell gate. The top surface of the memory cell gate and a top surface of the silicide contact pad are recessed relative to a top surface of the metal gate and top surfaces of the dielectric regions. A method of manufacturing the integrated circuit is also provided.

Claims

1. An integrated circuit for an embedded flash memory device, said integrated circuit comprising:

a semiconductor substrate including a memory region and a logic region adjacent to the memory region;

a logic device arranged over the logic region and including a metal gate separated from the semiconductor substrate by a material having a dielectric constant exceeding 3.9;

a flash memory cell device arranged over the memory region, the flash memory cell device including a memory cell gate electrically insulated on opposing sides by corresponding dielectric regions; and

a silicide contact pad arranged over a top surface of the memory cell gate, wherein the top surface of the memory cell gate and a top surface of the silicide contact pad are recessed relative to a top surface of the metal gate and top surfaces of the dielectric regions.

2. The integrated circuit according to claim 1, wherein the memory cell gate is one of a memory gate, a select gate, an erase gate, a word line, and a control gate.

3. The integrated circuit according to claim 1, wherein the flash memory cell device includes:

a select gate;

a memory gate spaced from the memory gate; and

a charge trapping dielectric arranged under the memory gate and between neighboring sidewalls of the select and memory gates;

wherein the memory cell gate is the select gate or the memory gate, and one of the dielectric regions includes the charge trapping dielectric.

4. The integrated circuit according to claim 1, wherein the flash memory cell device includes:

a floating gate;

an erase gate and a word line spaced from the floating gate on opposite sides of the floating gate;

a control gate arranged over the floating gate; and

a floating gate spacer arranged between neighboring sidewalls of the control gate, the word line, and the erase gate;

wherein the memory cell gate is the floating gate or the erase gate, and one of the dielectric regions includes the floating gate spacer.

5. The integrated circuit according to claim 1, wherein at least one of:

the top surface of the memory cell gate is recessed about 10-500 Angstroms (A) below the top surface of the metal gate; and

the top surface of the memory cell gate is recessed about 100-300 A below the top surfaces of the dielectric regions.

6. The integrated circuit according to claim 1, wherein

the top surface of the silicide contact pad is recessed about 50-100 Angstroms below the top surfaces of the dielectric regions.

7. The integrated circuit according to claim 1, wherein the top surface of the memory cell gate is substantially planar or the top surface of the silicide contact pad is substantially planar.

8. The integrated circuit according to claim 1, wherein the top surfaces of the dielectric regions are recessed below the top surface of the metal gate.

9. The integrated circuit according to claim 1, further including:

a dielectric mask at least partially covering the logic region, while leaving the memory region uncovered.

10-19. -19. (canceled)

20. An integrated circuit for an embedded flash memory device, said integrated circuit comprising:

a semiconductor substrate including a memory region and a logic region adjacent to the memory region, the memory region including a common source/drain region and a pair of individual source/drain regions arranged on opposite sides of the common source/drain region;

a logic device arranged over the logic region and including a metal gate separated from the semiconductor substrate by a material having a dielectric constant exceeding 3.9; and

a pair of flash memory cell devices arranged over the memory region, wherein each flash memory cell device corresponds to one of the individual source/drain regions and includes;

a select gate and a memory gate arranged between the common source/drain region and the corresponding individual source/drain region; and

a charge trapping dielectric arranged between neighboring sidewalls of the memory and select gates, and arranged under the memory gate; and

silicide contact pads respectively arranged over top surfaces of the select and memory gates, wherein top surfaces of the silicide contact pads are recessed relative to a top surface of the metal gate and top surfaces of the charge trapping dielectrics

21. The integrated circuit according to claim 20, wherein at least one of:

the top surfaces of the select and memory gates are recessed about 10-500 Angstroms (A) below the top surface of the metal gate; and

the top surfaces of the select and memory gates are recessed about 100-300 A below the top surfaces of the charge trapping dielectrics.

22. The integrated circuit according to claim 20, wherein the top surfaces of the select and memory gates are substantially planar, and the top surfaces of the silicide contact pads are substantially planar.

23. The integrated circuit according to claim 20, wherein the top surfaces of the charge trapping dielectrics are recessed below the top surface of the metal gate.

24. The integrated circuit according to claim 20, further including:

a dielectric mask at least partially covering the logic region, while leaving the memory region uncovered.

25. An integrated circuit for an embedded flash memory device, said integrated circuit comprising:

a flash memory cell device arranged over a semiconductor substrate, the flash memory cell device including a memory cell gate electrically insulated on opposing sides by corresponding dielectric layers; and

a silicide contact pad arranged over a top surface of the memory cell gate, wherein the top surface of the memory cell gate and a top surface of the silicide contact pad are recessed relative to top surfaces of the dielectric layers.

26. The integrated circuit according to claim 25, further comprising:

a logic device arranged over the semiconductor substrate and including a metal gate separated from the semiconductor substrate by a material having a dielectric constant exceeding about 3.9;

wherein the top surfaces of the memory cell gate and the silicide contact pad are recessed relative to a top surface of the metal gate.

27. The integrated circuit according to claim 26, wherein the top surfaces of the dielectric layers are recessed below the top surface of the metal gate.

28. The integrated circuit according to claim 26, further comprising:

a dielectric mask covering the logic device, while leaving the flash memory cell device uncovered; and

an interlayer dielectric (ILD) layer covering the dielectric mask and the flash memory cell device.

29. The integrated circuit according to claim 25, wherein the flash memory cell device includes:

an erase gate arranged over a first source/drain region of the semiconductor substrate;

a wordline arranged between the first source/drain region and a second source/drain region of the semiconductor substrate;

a floating gate arranged between the wordline and the erase gate;

a control gate arranged over the floating gate; and

dielectric layers arranged on opposing sides of the erase gate, the wordline, the floating gate, and the control gate; and

wherein the memory cell gate is one of the wordline, the erase gate, and the control gate.

30. The integrated circuit according to claim 25, wherein the flash memory cell device includes:

a select gate arranged between first and second source/drain regions of the semiconductor substrate;

a memory gate arranged between the select gate and the second source/drain region; and

dielectric layers arranged on opposing sides of the select and memory gates, wherein the dielectric layers are configured to isolate the select and memory gates from one another; and

wherein the memory cell gate is one of the select and memory gates.