Semiconductor Memory Having Both Volatile and Non-Volatile Functionality and Method of Operating

• US 20170025534A1
• Filed: 09/16/2016
• Published: 01/26/2017
• Est. Priority Date: 10/24/2007
• Status: Active Grant

• Current Assignee: Zeno Semiconductor, Inc.
• Original Assignee: Zeno Semiconductor, Inc.
• Inventors: Widjaja, Yuniarto
• Granted Patent: US 9,761,311 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G11C 11/404 with one charge-transfer gate, e.g. MOS transistor, per cell
• CPC Class Codes: G11C 14/0018 whereby the nonvolatile element is an EEPROM element, e.g. a floating gate or metal-nitride-oxide-silicon [MNOS] transistor
• CPC Class Codes: G11C 16/0408 comprising cells containing floating gate transistors G11C16/0483, G11C16/0491 take precedence
• CPC Class Codes: G11C 16/0466 comprising cells with charge storage in an insulating layer, e.g. metal-nitride-oxide-silicon [MNOS], silicon-oxide-nitride-oxide-silicon [SONOS] G11C16/0483, G11C16/0491 take precedence
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series
• CPC Class Codes: G11C 16/225 Preventing erasure, programming or reading when power supply voltages are outside the required ranges
• CPC Class Codes: G11C 2211/4016 Memory devices with silicon-on-insulator cells
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 29/0649 Dielectric regions, e.g. SiO2 regions, air gaps
• CPC Class Codes: H01L 29/40114 the electrodes comprising a conductor-insulator-conductor-insulator-semiconductor structure
• CPC Class Codes: H01L 29/40117 the electrodes comprising a charge-trapping insulator
• CPC Class Codes: H01L 29/42324 Gate electrodes for transistors with a floating gate
• CPC Class Codes: H01L 29/4234 Gate electrodes for transistors with charge trapping gate insulator
• CPC Class Codes: H01L 29/66825 with a floating gate H01L29/6684 takes precedence
• CPC Class Codes: H01L 29/66833 with a charge trapping gate insulator, e.g. MNOS transistors
• CPC Class Codes: H01L 29/7841 with floating body, e.g. programmable transistors
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7885 Hot carrier injection from the channel
• CPC Class Codes: H01L 29/7887 Programmable transistors with more than two possible different levels of programmation
• CPC Class Codes: H01L 29/792 : with charge trapping gate insulator, e.g. MNOS-memory transistors
• CPC Class Codes: H01L 29/7923 : Programmable transistors with more than two possible different levels of programmation
• CPC Class Codes: H10B 12/00 : Dynamic random access memory [DRAM] devices
• CPC Class Codes: H10B 12/056 : the transistor being a FinFET
• CPC Class Codes: H10B 12/20 : DRAM devices comprising floating-body transistors, e.g. floating-body cells
• CPC Class Codes: H10B 12/36 : the transistor being a FinFET
• CPC Class Codes: H10B 12/50 : Peripheral circuit region structures
• CPC Class Codes: H10B 41/30 : characterised by the memory core region
• CPC Class Codes: H10B 41/40 : characterised by the peripheral circuit region
• CPC Class Codes: H10B 41/42 : Simultaneous manufacture of periphery and memory cells
• CPC Class Codes: H10B 43/30 : characterised by the memory core region
• CPC Class Codes: H10B 43/40 : characterised by the peripheral circuit region

Abstract

Semiconductor memory having both volatile and non-volatile modes and methods of operation. A semiconductor storage device includes a plurality of memory cells each having a floating body for storing, reading and writing data as volatile memory. The device includes a floating gate or trapping layer for storing data as non-volatile memory, the device operating as volatile memory when power is applied to the device, and the device storing data from the volatile memory as non-volatile memory when power to the device is interrupted.

Claims

1-22. -22. (canceled)

23. A semiconductor memory cell comprising:

a fin structure extending from a substrate, said fin structure comprising a floating body region configured to be charged to a level indicative of a state of the memory cell to store the state as volatile memory; and

a floating gate or trapping layer insulated from said floating body region and being configured to receive transfer of data stored by the volatile memory and store the data as nonvolatile memory;

wherein said charge stored in said floating body region determines a charge stored in said floating gate or trapping layer upon said transfer of data.

24. The semiconductor memory cell of claim 23, further comprising first and second regions in electrical contact with said floating body region, wherein each of said first and second regions has a conductivity type different from a conductivity type of said floating body region.

25. The semiconductor memory cell of claim 23, further comprising an isolation layer that isolates said floating body region from said substrate.

26. The semiconductor memory cell of claim 25, wherein said isolation layer comprises a buried oxide insulating layer.

27. The semiconductor memory cell of claim 25, wherein said isolation layer comprises a buried layer having a conductivity type from a conductivity type of said floating body region.

28. The semiconductor memory cell of claim 23, wherein said floating gate or trapping layer is insulated from said floating body region by an insulating layer.

29. The semiconductor memory cell of claim 23, further comprising a control gate insulated from said floating gate or trapping layer by an insulating layer.

30. A semiconductor memory array comprising:

a plurality of semiconductor memory cells arranged in a matrix of rows and columns, wherein each said semiconductor memory cell comprises;

a fin structure extending from a substrate, said fin structure comprising a floating body region configured to be charged to a level indicative of a state of the memory cell to store the state as volatile memory; and

a floating gate or trapping layer insulated from said floating body region and being configured to receive transfer of data stored by the volatile memory and store the data as nonvolatile memory;

wherein when a first memory cell of said plurality of semiconductor memory cells is in a first charge level and a second memory cell of said plurality of semiconductor memory cells is in a second charge level, upon said transfer of data, said first memory cell stores a first nonvolatile memory state and second memory cell stores a second nonvolatile memory state, said first and second nonvolatile memory states being non-algorithmically determined by said first and second charge levels of said first and second memory cells, respectively.

31. The semiconductor memory array of claim 30, wherein each said semiconductor memory cell further comprises first and second regions in electrical contact with said floating body region, wherein each of said first and second regions has a conductivity type different from a conductivity type of said floating body region.

32. The semiconductor memory array of claim 30, wherein each said semiconductor memory cell further comprises an isolation layer that isolates said floating body region from said substrate.

33. The semiconductor memory array of claim 32, wherein said isolation layer comprises a buried oxide insulating layer.

34. The semiconductor memory array of claim 32, wherein said isolation layer comprises a buried layer having a conductivity type different from a conductivity type of said floating body region.

35. The semiconductor memory array of claim 30, wherein said floating gate or trapping layer is insulated from said floating body region by an insulating layer.

36. The semiconductor memory array of claim 30, wherein each said semiconductor memory cell further comprises a control gate insulated from said floating gate or trapping layer by an insulating layer.

37. A semiconductor memory cell comprising:

a fin structure extending from a substrate, said fin structure comprising a floating body region configured to be charged to a level indicative of a state of the memory cell to store the state as volatile memory; and

a floating gate or trapping layer insulated from said floating body region and being configured to receive transfer of data stored by the volatile memory and store the data as nonvolatile memory;

wherein upon restoration of power to said memory cell, said floating body region stores charge based on nonvolatile memory data stored in said floating gate or trapping layer.

38. The semiconductor memory cell of claim 37, further comprising first and second regions in electrical contact with said floating body region, wherein each of said first and second regions has a conductivity type different from a conductivity type of said floating body region.

39. The semiconductor memory cell of claim 37, further comprising an isolation layer that isolates said floating body region from said substrate.

40. The semiconductor memory cell of claim 39, wherein said isolation layer comprises a buried oxide insulating layer.

41. The semiconductor memory cell of claim 39, wherein said isolation layer comprises a buried layer having a conductivity type different from a conductivity type of said floating body region.

42. The semiconductor memory cell of claim 37, wherein said floating gate or trapping layer is insulated from said floating body region by an insulating layer.

43. The semiconductor memory cell of claim 37, further comprising a control gate insulated from said floating gate or trapping layer by an insulating layer.