Storage and calculation oriented Sensor-Switch type SONOS FLASH unit structure

Abstract

The invention relates to a Sense-Switch type SONOS (Silicon Oxide Nitride Oxide Semiconductor) FLASH unit structure for storage and calculation, and belongs to the field of microelectronic integrated circuits. Comprising a Sense type SONOS FLASH programming / erasing tube and a Switch type SONOS FLASH signal transmission tube, and the programming / erasing tube and the signal transmission tube realize on-off state control of the signal transmission tube by the programming / erasing tube in a gate charge sharing manner. The Sensor-Switch type SONOS FLASH unit provided by the invention has the advantages that the structure is simple, the SONOS FLASH unit is compatible with a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) process, and the area is small.

Description

Technical Field

[0001] The invention belongs to the technical field of microelectronic integrated circuits, and in particular relates to a Sense-Switch type SONOS FLASH unit structure for storage and calculation. Background Art

[0002] SONOS FLASH storage and computing devices achieve data changes by injecting or releasing electrons into the gate. Compared with volatile memory devices (SRAM and DRAM) and new memory devices (PCRAM, MRAM, ReRAM, etc.), they have the advantages of non-volatility, low power consumption, high speed, high reliability, and high process maturity, providing important support for their application in edge computing, Internet of Things, and artificial intelligence.

[0003] However, the development of SONOS FLASH storage-computing integrated devices is still constrained in many aspects. First, as the size of integrated circuit manufacturing process nodes is further reduced, planar transistors will form more serious leakage currents, and the area of ​​traditional 2T-type FLASH storage-computing integrated computing units is difficult to further shrink. Secondly, the current of the storage-computing integrated array composed of storage-computing integrated computing units is too large, which will increase the area and power consumption of the analog-to-digital converter. Finally, the programming current of the FLASH storage-computing integrated device varies greatly when the current value is relatively small, making this range difficult to directly apply to storage-computing integrated circuits. Summary of the invention

[0004] The purpose of the present invention is to provide a Sense-Switch type SONOS FLASH unit structure for storage and computing, so as to solve the problems that the size of the SONOS FLASH type storage and computing integrated computing unit is difficult to miniaturize, the working current of the storage and computing integrated computing unit is large, and the current variation range is large during the programming process of the FLASH type storage and computing integrated device, so as to realize the preparation of a compact storage and computing integrated computing unit.

[0005] In order to solve the above technical problems, the present invention provides a Sense-Switch type SONOS FLASH unit structure for storage and computing, wherein the Sense-Switch type SONOS FLASH unit is a trench structure; comprising: 2 SONOS FLASH tubes, namely the Sense type SONOS FLASH tube and the Switch type SONOS FLASH tube; Ion implantation is performed at the bottom of the trench-type Sense-Switch SONOS FLASH unit to prevent the Sense-type SONOS FLASH tube and the Switch-type SONOS FLASH tube from communicating with each other; The source and drain ends of the Sense-type SONOS FLASH tube and the Switch-type SONOS FLASH tube are located on the side wall of the trench-type Sense-Switch-type SONOS FLASH unit; The gate terminal is shared between the Sense type SONOS FLASH tube and the Switch type SONOS FLASH tube.

[0006] Preferably, the two SONOS FLASH tubes are both SONOS-type pFLASH tubes.

[0007] Preferably, the two SONOS FLASH tubes are specifically a Sense-type SONOS FLASH programming / erasing tube and a Switch-type SONOS FLASH signal transmission tube, and the switching state control of the signal transmission tube by the programming / erasing tube is achieved by sharing gate charge.

[0008] Preferably, the ion implantation is performed at the bottom of the trench-type Sense-Switch type SONOS FLASH unit, and the specific structure formed includes: A silicon-based substrate is provided, wherein a trench structure is formed in the silicon-based substrate, a gate-end tunnel oxide layer and a nitride layer are formed in the trench, and an oxide layer is deposited on the nitride layer to form an oxide-nitride-oxide structure; The drain end and source end of the Sense type SONOS FLASH tube and the drain end and source end of the Switch type SONOS FLASH tube are formed to lead out; A gate terminal lead is formed at the gate terminal of the Sense type SONOS FLASH tube and the Switch type SONOS FLASH tube.

[0009] Preferably, it includes three working modes: programming, erasing and reading; Through programming of Sense-type SONOS FLASH tubes, the gate terminal charging of Sense-type SONOS FLASH tubes and Switch-type SONOS FLASH tubes is realized; By erasing the Sense-type and Switch-type SONOS FLASH tubes, the gate-end discharge of the Sense-type SONOS FLASH tubes and the Switch-type SONOS FLASH tubes is realized; After the Sense-type SONOS FLASH tube is programmed, potential transmission of the Sense-Switch SONOS FLASH unit is achieved by applying potential to the source and drain ends of the Switch-type SONOS FLASH tube.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The Sense-Switch SONOS FLASH unit structure of the present invention includes a Sense-type SONOS FLASH programming / erasing tube and a Switch-type SONOS FLASH signal transmission tube; the programming / erasing tube and the signal transmission tube realize the switching state control of the programming / erasing tube on the signal transmission tube by sharing gate charge. The Sense-Switch SONOS FLASH unit proposed by the present invention has the advantages of simple structure, compatibility with CMOS process and small area. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the Sense-Switch type SONOS FLASH unit of the present invention.

[0012] Figure 2 1 is a structural diagram of a Sense-Switch type SONOS FLASH unit of the present invention; wherein (a) is a structural diagram of a SONOS FLASH unit, and (b) is a cross-sectional view of (a) along the AA direction.

[0013] Figure 3 It is a working schematic diagram of the Sense-Switch type SONOS FLASH unit of the present invention. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0015] like Figure 1 As shown in the figure: a Sense-Switch type SONOS FLASH unit structure for storage and computing provided by an embodiment of the present invention specifically includes two SONOS FLASH devices, namely a Sense type SONOS FLASH programming / erasing tube and a Switch type SONOS FLASH signal transmission tube. The Sense type SONOS FLASH tube includes a Sense type SONOS FLASH tube drain terminal (D Sense ), Sense type SONOS FLASH tube source end (S Sense ), Sense type SONOS FLASH tube substrate end (B Sense ); The switch type SONOS FLASH signal transmission tube includes a switch type SONOS FLASH signal transmission tube drain end (D Switch )、Switch type SONOS FLASH signal transmission tube source end (SSwitch )、Switch type SONOS FLASH signal transmission tube substrate end (B Switch ); Sense type SONOS FLASH tube and Switch type SONOS FLASH tube share the gate (G).

[0016] like Figure 2 As shown: The Sense-Switch SONOS FLASH unit for storage and computing provided in the embodiment of the present invention is a trench structure, wherein the source and drain ends of the Sense-Switch SONOS FLASH tube and the Switch-type SONOS FLASH tube are located on the side wall of the trench Sense-Switch SONOS FLASH unit; ion implantation is performed at the bottom of the trench Sense-Switch SONOS FLASH unit to prevent the Sense-type SONOS FLASH tube and the Switch-type SONOS FLASH tube from communicating with each other. The specific structure is: A trench structure is formed in a silicon substrate 1, a gate tunnel oxide layer 2 and a nitride layer 3 are formed in the trench, and an oxide layer 4 is deposited on the nitride layer to form an oxide-nitride-oxide structure; drain and source leads are formed at the drain end 5 and source end 6 of the Sense type SONOS FLASH tube and the drain end 7 and source end 8 of the Switch type SONOS FLASH tube, and a gate lead 9 is formed at the gates of the Sense type SONOS FLASH tube and the Switch type SONOS FLASH tube.

[0017] like Figure 3 As shown: The Sense-Switch SONOS FLASH unit for storage and calculation of the present invention includes three working modes: programming, erasing and reading. During the programming process, the Sense-type SONOS FLASH tube is used to store electrons in the nitride; during the erasing process, the Sense-type SONOS FLASH tube and the Switch-type SONOS FLASH tube are used to release electrons in the nitride; during the reading process, the Switch-type SONOS FLASH tube is used to control the working state.

[0018] like Figure 1As shown in the figure, in view of the shared gates of the Sense-type SONOS FLASH and the Switch-type SONOS FLASH, during the programming process, electrons are mainly stored in the gate on the Sense-type SONOS FLASH side, that is, capacitor C1, while no electrons are stored in the gate on the Switch-type SONOS FLASH side, so it is equivalent to having an additional capacitor C2. Since electrons are mainly stored in the nitride on the side of the Sense-type SONOS FLASH tube, compared with the Switch-type SONOS FLASH tube, it is equivalent to adding an additional capacitor C2 at the gate end, so as to achieve fine control of the gate voltage of the Switch-type SONOS FLASH tube, and achieve the purpose of finely controlling the programming current change amplitude of the Switch-type SONOS FLASH tube. At the same time, under the condition of realizing fine control of the current of the Switch-type SONOS FLASH tube, the use of large current of the Switch-type SONOS FLASH tube is also reduced, which helps to reduce the design area and power consumption of the analog-to-digital conversion circuit.

[0019] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A Sense-Switch SONOS FLASH unit structure for storage and computing, characterized in that: The Sense-Switch type SONOS FLASH unit is a trench type structure; include: 2 SONOS FLASH tubes, namely the Sense type SONOS FLASH tube and the Switch type SONOS FLASH tube; Ion implantation is performed at the bottom of the trench-type Sense-Switch SONOS FLASH unit to prevent the Sense-type SONOS FLASH tube and the Switch-type SONOS FLASH tube from communicating with each other; The source and drain ends of the Sense-type SONOS FLASH tube and the Switch-type SONOS FLASH tube are located on the side wall of the trench-type Sense-Switch-type SONOS FLASH unit; The gate terminal is shared between the Sense type SONOS FLASH tube and the Switch type SONOS FLASH tube.

2. A Sense-Switch type SONOS FLASH unit structure for storage and computing as claimed in claim 1, characterized in that: The two SONOS FLASH tubes are both SONOS-type pFLASH tubes.

3. A Sense-Switch type SONOS FLASH unit structure for storage and computing as claimed in claim 2, characterized in that: The two SONOS FLASH tubes are specifically a Sense-type SONOS FLASH programming / erasing tube and a Switch-type SONOS FLASH signal transmission tube, and the switching state control of the signal transmission tube by the programming / erasing tube is realized by sharing gate charge.

4. The Sense-Switch SONOS FLASH unit structure for storage and computing as claimed in claim 1, characterized in that: The specific structure formed by performing ion implantation at the bottom of the trench type Sense-Switch type SONOS FLASH unit includes: A silicon-based substrate is provided, wherein a trench structure is formed in the silicon-based substrate, a gate-end tunnel oxide layer and a nitride layer are formed in the trench, and an oxide layer is deposited on the nitride layer to form an oxide-nitride-oxide structure; The drain end and source end of the Sense type SONOS FLASH tube and the drain end and source end of the Switch type SONOS FLASH tube are formed to lead out; A gate terminal lead is formed at the gate terminal of the Sense type SONOS FLASH tube and the Switch type SONOS FLASH tube.

5. The Sense-Switch type SONOS FLASH unit structure for storage and computing as claimed in claim 1, characterized in that: Includes three working modes: programming, erasing and reading; Through programming of Sense-type SONOS FLASH tubes, the gate terminal charging of Sense-type SONOS FLASH tubes and Switch-type SONOS FLASH tubes is realized; By erasing the Sense-type and Switch-type SONOS FLASH tubes, the gate-end discharge of the Sense-type SONOS FLASH tubes and the Switch-type SONOS FLASH tubes is realized; After the Sense-type SONOS FLASH tube is programmed, potential transmission of the Sense-Switch SONOS FLASH unit is achieved by applying potential to the source and drain ends of the Switch-type SONOS FLASH tube.

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