TWI713860B - Flash memory apparatus and method for programming thereof - Google Patents

Abstract

A flash memory device and a programming method thereof are provided. The programming method includes: setting an initial program voltage, and performing a first programming operation on a plurality of flash memory cells according to an initial program voltage; after the first programming operation, detecting a threshold voltages of the flash memory cells and obtaining a highest threshold voltage; setting a target threshold voltage to generate a second program voltage according to the target threshold voltage, the initial voltage, and the highest threshold voltage; performing a second programming operation on the plurality of flash memory cells according to the second program voltage; after the second programming operation, verifying the plurality of flash memory cells by same or different verify voltage, and based on the second program voltage, performing an increment operation according to a programming step value to generate at least one third program voltage; performing at least one third programming operation on the plurality of flash memory cells according to the at least one third program voltage; and enabling the plurality of flash memory cells pass the verify voltage according to a final program voltage.

Description

Flash memory device and its programming method

The invention relates to a flash memory device and its programming method.

With the popularization of electronic products, providing high-quality data storage media has become one of the important specifications of electronic products in response to the large amount of information needs of users. In the current technical field, flash memory, which can provide data writing and reading capabilities, has become an essential data storage medium for electronic products.

When programming the flash memory, it is more difficult to set the programming voltage for the first time. When the programming voltage for the first time is set too large, it is easy to produce poor threshold voltage distribution of the memory cell. The first programming voltage setting is too small, resulting in long programming time. In addition, based on the distribution of memory cells at multiple positions in the integrated circuit, the results generated by the programming action are easily related to the placement positions of the memory cells, and the critical voltage distribution of the programming memory cells cannot be optimized. In addition, based on the characteristic changes of memory cells after multiple erasing and programming, the result of programming is easily related to the number of erasing and programming of memory cells.

The invention provides a flash memory device and a programming method thereof, which can control the critical voltage distribution state of the programmed memory cell and optimize the programming time of the flash memory cell.

The present invention provides a programming method of a flash memory, which includes: setting an initial programming voltage, and performing a first programming action on a plurality of flash memory cells according to the initial programming voltage; after the first programming action , Detect the threshold voltage of the flash memory cell and obtain the highest threshold voltage; set the target threshold voltage, and generate the second programmed voltage according to the target threshold voltage, the initial programmed voltage, and the highest threshold voltage; The flash memory cell performs a second programming action; after the second programming action, based on the second programming voltage, an incremental action is performed according to the programming step value to generate at least one third programming voltage; and according to at least one The third programming voltage performs at least one third programming action on the flash memory cell.

The present invention provides a flash memory device, which includes a flash memory and a controller. The flash memory has multiple flash memory cells. The controller is coupled to the flash memory and used to: set the initial programming voltage, and perform the first programming action on the multiple flash memory cells according to the initial programming voltage; after the first programming action, detect Measure the threshold voltage of the flash memory cell and obtain the highest threshold voltage; set the target threshold voltage, and generate the second programmed voltage according to the target threshold voltage, the initial programmed voltage and the highest threshold voltage; compare the flash memory according to the second programmed voltage The cell performs a second programming action; after the second programming action, based on the second programming voltage, an incremental action is performed according to the programming step value to generate at least one third programming voltage; and according to at least one third programming voltage; The programming voltage performs at least one third programming action on the flash memory cell.

Based on the above, the flash memory device provided by the present invention controls the distribution range of the threshold voltage of the programmed flash memory cell through multiple programming actions on the flash memory cell. In this way, a lower initial programming can be set, and the flash memory cell can be programmed by gradually adjusting the initial programming voltage, thereby optimizing the threshold voltage distribution of the programming memory cell.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

FIG. 1 illustrates a flowchart of a programming method of a flash memory according to an exemplary embodiment of the present invention. Please refer to FIG. 1, in step S101, an initial programming voltage is set, and a plurality of flash memory cells in the flash memory are programmed for the first time according to the initial programming voltage. Please refer to FIG. 1 and FIG. 2A at the same time. FIG. 2A illustrates a schematic diagram of the threshold voltage distribution state of each programming step of the flash memory according to an exemplary embodiment of the present invention. Specifically, before the first programming action is performed, the threshold voltage distribution of the flash memory cell is in the erased state Z0, and through the execution of step S101, the threshold voltage distribution of the flash memory cell may be changed to the program State Z1 (that is, the threshold voltage of the programmed flash memory cell at this time is less than the target threshold voltage).

。藉此，依據讀取電壓RV1對快閃記憶胞進行讀取的驗證動作，以判斷快閃記憶胞的臨界電壓是否皆小於讀取電壓RV1。若驗證出所有的快閃記憶胞的臨界電壓皆小於讀取電壓RV1，便將讀取電壓RV1設定為最大臨界電壓值RV。若驗證出所有的快閃記憶胞的臨界電壓未皆小於讀取電壓RV1，使索引值n遞增1，並在索引值n不大於臨界值N的條件下，重新進行上述讀取的驗證動作。步驟S105設定目標臨界電壓，依據目標臨界電壓、初始程式化電壓以及最高臨界電壓以產第二程式化電壓，其中目標臨界電壓為預設的臨界電壓的最大值。具體而言，可預先設定目標臨界電壓VTh，並計算出第二程式化電壓V1等於

。其中，V0為步驟S101中設定的初始程式化電壓，Voffest為預設的偏移電壓值。It is worth noting that the setting method of the initial programming voltage is related to the process parameters of the memory. The engineer can set a relatively low initial programming voltage according to the process parameters of the memory to target the flash memory in the erased state. Cells perform programmed actions. Then, in step S103, after the first programming action, the threshold voltage of the flash memory cell is detected and the highest threshold voltage among the threshold voltages in the flash memory cell is obtained. Specifically, since the threshold voltage of the flash memory cell may be distributed in the programmed state Z1 after the first programming action is performed, the highest threshold voltage RV of the flash memory cell can be obtained by performing step S103. Specifically, the index value n can be initialized, the initial read voltage RV0 and the read step value Vstep can be set, and the read voltage RV1 can be set equal to

. In this way, a verification operation of reading the flash memory cell is performed according to the reading voltage RV1 to determine whether the threshold voltage of the flash memory cell is less than the reading voltage RV1. If it is verified that the threshold voltages of all flash memory cells are less than the read voltage RV1, the read voltage RV1 is set to the maximum threshold voltage RV. If it is verified that the threshold voltages of all the flash memory cells are not less than the read voltage RV1, the index value n is incremented by 1, and under the condition that the index value n is not greater than the threshold value N, the above-mentioned read verification operation is performed again. Step S105 sets a target threshold voltage, and generates a second programming voltage according to the target threshold voltage, the initial programming voltage and the highest threshold voltage, where the target threshold voltage is the maximum value of the preset threshold voltage. Specifically, the target threshold voltage VTh can be preset, and the second programmed voltage V1 can be calculated to be equal to

. Among them, V0 is the initial programming voltage set in step S101, and Voffest is the preset offset voltage value.

It is worth noting that the preset offset voltage value Voffest can be set by engineers according to requirements and the actual state of the flash memory. The preset offset voltage value Voffest can be greater than, less than, or equal to 0 volts. .

1。其中，V1為第二程式化電壓，m為程式化次數。最後，步驟S111依據至少一第三程式化電壓V2對快閃記憶胞進行一次或多次的第三次程式化動作。請同時參看圖2C，其中圖2C說明根據本發明的示範性實施例的快閃記憶體的各程式化動作的臨界電壓分佈狀態示意圖。具體而言，透過步驟S318~S331或步驟 S416~S429的進行，可將快閃記憶胞的臨界電壓分佈控制在程式化的狀態Z3，其中狀態Z3被控制在第一驗證電壓PV以及目標臨界電壓VTh間，而第一驗證電壓PV以及第二驗證電壓PV1之間具有一個偏移電壓值OT。其中，步驟S318~S331以及步驟S416~S429將在下述的實施例中有進一步的描述。Then, step S107 performs a second programming action on the flash memory cell according to the second programming voltage V1 obtained in step S105. Please refer to FIG. 1 and FIG. 2B at the same time, where FIG. 2B illustrates a schematic diagram of the threshold voltage distribution state of each programming action of the flash memory according to an exemplary embodiment of the present invention. Specifically, before the second programming action is performed, the threshold voltage distribution of the flash memory cell is in the programmed state Z1, and through the execution of step S107, the threshold voltage distribution of the flash memory cell is changed to the programmed state State Z2 (ie, the threshold voltage of the flash memory cell is not all greater than the second verification voltage PV1). In step S109, after the second programming operation, the second programming voltage is incremented according to the programming step value and at least one third programming voltage is generated. Specifically, the programmed step value Vstep1 can be preset to calculate that the third programmed voltage V2 is equal to

1. Among them, V1 is the second programming voltage, and m is the number of programming. Finally, step S111 performs one or more third programming actions on the flash memory cell according to at least one third programming voltage V2. Please refer to FIG. 2C at the same time, in which FIG. 2C illustrates a schematic diagram of the threshold voltage distribution state of each programming action of the flash memory according to an exemplary embodiment of the present invention. Specifically, by performing steps S318~S331 or steps S416~S429, the threshold voltage distribution of the flash memory cell can be controlled in a programmed state Z3, wherein the state Z3 is controlled at the first verification voltage PV and the target threshold voltage There is an offset voltage value OT between the first verification voltage PV and the second verification voltage PV1. Among them, steps S318 to S331 and steps S416 to S429 will be further described in the following embodiments.

Through the above steps, the present invention can program the flash memory by gradually adjusting the programming voltage to control the threshold voltage of the flash memory within a preset range (ie, the first verification voltage PV and The target threshold voltage VTh), and then optimize the threshold voltage distribution of the flash memory.

FIG. 3 illustrates a flowchart of a programming method of a flash memory according to another exemplary embodiment of the present invention. Please refer to FIG. 3, step S301 initializes the index value n to be equal to zero. In step S303, the initial programming voltage V0 is set, and the flash memory cell is programmed according to the initial programming voltage V0. Step S305 performs a corresponding verification action on the flash memory cell according to the first verification voltage PV, and is used to verify whether the programming actions of the flash memory cell have been completed. When all flash memory cells can pass the verification, the stylized action has been completed. In contrast, when not all flash memory cells can pass the verification (verification fails), step S307 is executed (that is, the threshold voltage of the flash memory cells is not all greater than the first verification voltage PV).

。步驟S309依據讀取電壓RV1對快閃記憶胞進行讀取的驗證動作，以判斷快閃記憶胞的臨界電壓是否皆小於讀取電壓RV1，若步驟S309驗證出所有的快閃記憶胞的臨界電壓皆小於讀取電壓RV1，則執行步驟S315，相對的，若步驟S309驗證出所有的快閃記憶胞的臨界電壓未皆小於讀取電壓RV1，使索引值n遞增1（步驟S311），並在索引值n不大於臨界值N的條件下（步驟S313），重新執行步驟S307以及S309。Step S307 sets the initial read voltage RV0 and the read step value Vstep, and sets the read voltage RV1 equal to

. Step S309 performs a verification operation of reading the flash memory cell according to the read voltage RV1 to determine whether the threshold voltage of the flash memory cell is less than the read voltage RV1. If step S309 verifies the threshold voltage of all the flash memory cells If both are less than the read voltage RV1, then perform step S315. On the other hand, if step S309 verifies that the threshold voltage of all flash memory cells is not less than the read voltage RV1, the index value n is incremented by 1 (step S311), Under the condition that the index value n is not greater than the critical value N (step S313), steps S307 and S309 are executed again.

Through steps S307 to S313, the threshold voltage of the flash memory cell is read and verified by increasing the read voltage RV1, and the maximum threshold voltage RV in the flash memory cell can be tracked. Here, by setting the size of the step value Vstep, the accuracy of tracking the maximum threshold voltage value RV and the tracking speed can be adjusted. Among them, when a relatively large step value Vstep is set, the maximum threshold voltage value RV can be calculated faster, and relatively, when a relatively small step value Vstep is set, a more accurate maximum threshold voltage value RV can be calculated.

On the other hand, in step S313, when it is determined that the index value n is greater than the threshold value N, the tracking operation of the maximum threshold voltage value RV is stopped, and step S315 is executed.

1。其中，Voffset1為預設的偏壓值。步驟S318依據第二程式化電壓V1對快閃記憶胞進行進一步的程式化動作。步驟S319依據第二驗證電壓PV1對快閃記憶胞進行對應的驗證動作。具體而言，在進一步的程式化動作後，依據第二驗證電壓PV1對快閃記憶胞進行對應的驗證動作，並用以驗證快閃記憶胞的程式化動作是否皆已完成。當所有的快閃記憶胞都可以通過驗證時，表示的程式化動作已完成。相對的，當非所有的快閃記憶胞都可以通過驗證（驗證失敗）時，則執行步驟S321（即，快閃記憶胞的臨界電壓未皆大於第二驗證電壓PV1）。Continuing the above description, step S315 starts to perform further stylized actions. By setting the target threshold voltage VTh in step S317, and calculating the second programmed voltage V1 equal to

1. Among them, Voffset1 is the preset bias value. Step S318 performs a further programming action on the flash memory cell according to the second programming voltage V1. Step S319 performs a corresponding verification action on the flash memory cell according to the second verification voltage PV1. Specifically, after further programming actions, corresponding verification actions are performed on the flash memory cells according to the second verification voltage PV1, and used to verify whether the programming actions of the flash memory cells have been completed. When all flash memory cells can pass the verification, the stylized action has been completed. In contrast, when not all the flash memory cells can pass the verification (verification fails), step S321 is executed (that is, the threshold voltage of the flash memory cells is not all greater than the second verification voltage PV1).

。步驟S325依據第三程式化電壓V2對快閃記憶胞進行更進一步的程式化動作。步驟S327依據第一驗證電壓PV對快閃記憶胞進行對應的驗證動作。具體而言，在更進一步的程式化動作後，依據第一驗證電壓PV對快閃記憶胞進行對應的驗證動作，並用以驗證快閃記憶胞的程式化動作是否皆已完成。當所有的快閃記憶胞都可以通過驗證時，表示的程式化動作已完成。相對的，當非所有的快閃記憶胞都可以通過驗證（驗證失敗）時（即，快閃記憶胞的臨界電壓未皆大於第一驗證電壓PV），使索引值m遞增1（步驟S329），並在索引值m不大於臨界值M的條件下（步驟S331），重新執行步驟S323、S325以及S327。Next, step S321 initializes the index value m to be equal to 1. Step S323 presets the programming step value Vstep1 to set the third programming voltage V2, and calculates that the third programming voltage V2 is equal to

. Step S325 performs a further programming action on the flash memory cell according to the third programming voltage V2. Step S327 performs a corresponding verification action on the flash memory cell according to the first verification voltage PV. Specifically, after a further programming action, a corresponding verification action is performed on the flash memory cell according to the first verification voltage PV, and used to verify whether the programming action of the flash memory cell has been completed. When all flash memory cells can pass the verification, the stylized action has been completed. In contrast, when not all flash memory cells can pass the verification (verification fails) (that is, the threshold voltage of the flash memory cells is not all greater than the first verification voltage PV), the index value m is incremented by 1 (step S329) , And under the condition that the index value m is not greater than the critical value M (step S331), steps S323, S325, and S327 are executed again.

Through the process of step S323 to step S331, by increasing the third programming voltage V2 to program and verify the flash memory cell, the final threshold voltage distribution of the flash memory cell can be controlled to the verification voltage and the target threshold voltage VTh between.

FIG. 4 illustrates a flowchart of a programming method of a flash memory according to another exemplary embodiment of the present invention. Please refer to FIG. 4, step S401 initializes the index value n to be equal to zero. In step S403, the initial programming voltage V0 is set, and the flash memory cell is programmed according to the initial programming voltage V0. Step S405 performs a corresponding verification action on the flash memory cell according to the first verification voltage PV, and is used to verify whether the programming actions of the flash memory cell have been completed. When all flash memory cells can pass the verification, the stylized action has been completed. In contrast, when not all flash memory cells can pass the verification (verification fails), step S407 is executed (that is, the threshold voltage of the flash memory cells is not all greater than the first verification voltage PV).

。值得注意的，在步驟S407中，另同步進行第二程式化電壓V1的計算動作。其中，隨著讀取電壓RV1的遞增動作，第二程式化電壓V1可隨著索引值n的增加而進行追蹤的動作，並使第二程式化電壓V1=V0+(VTh – RV0) – Vstep × n + Voffset2，其中，RV0為初始驗證電壓，Voffset2為預設的偏壓值。Step S407 sets the initial read voltage RV0 and the step value Vstep, and sets the read voltage RV1 equal to

. It is worth noting that in step S407, the calculation of the second programmed voltage V1 is also performed simultaneously. Wherein, as the reading voltage RV1 increases, the second programmed voltage V1 can be tracked as the index value n increases, and the second programmed voltage V1=V0+(VTh – RV0) – Vstep × n + Voffset2, where RV0 is the initial verification voltage, and Voffset2 is the preset bias value.

Step S409 performs a verification operation of reading the flash memory cell according to the read voltage RV1 to determine whether the threshold voltage of the flash memory cell is less than the read voltage RV1. If step S409 verifies the threshold voltage of all the flash memory cells If both are less than the read voltage RV1, step S415 is executed. On the other hand, if step S409 verifies that the threshold voltage of all flash memory cells is not less than the read voltage RV1, the index value n is incremented by 1 (step S411), and Under the condition that the index value n is not greater than the critical value N (step S413), steps S407 and S409 are executed again.

It can be known from the above description that when the verification operation in step S409 is completed, the second programmed voltage V1 can also be generated synchronously.

Then, step S415 starts to perform further programming actions according to the second programming voltage V1. Step S416 performs a further programming action on the flash memory cell according to the second programming voltage V1. Step S417 performs a corresponding verification action on the flash memory cell according to the second verification voltage PV1. Specifically, after further programming actions, corresponding verification actions are performed on the flash memory cells according to the second verification voltage PV1, and used to verify whether the programming actions of the flash memory cells have been completed. When all flash memory cells can pass the verification, the stylized action has been completed. In contrast, when not all flash memory cells can pass the verification (verification fails), step S419 is executed (that is, the threshold voltage of the flash memory cells is not all greater than the second verification voltage PV1).

。步驟S423依據第三程式化電壓V2對快閃記憶胞進行更進一步的程式化動作。步驟S425依據第一驗證電壓PV對快閃記憶胞進行對應的驗證動作。具體而言，在更進一步的程式化動作後，依據第一驗證電壓PV對快閃記憶胞進行對應的驗證動作，並用以驗證快閃記憶胞的程式化動作是否皆已完成。當所有的快閃記憶胞都可以通過驗證時，表示的程式化動作已完成。相對的，當非所有的快閃記憶胞都可以通過驗證（驗證失敗）時（即，快閃記憶胞的臨界電壓未皆大於第一驗證電壓PV），使索引值m遞增1（步驟S427），並在索引值m不大於臨界值M的條件下（步驟S429），重新執行步驟S421、S423以及S425。Next, step S419 initializes the index value m to be equal to 1. Step S421 presets the programming step value Vstep1 to set the third programming voltage V2, and calculates that the third programming voltage V2 is equal to

. Step S423 performs a further programming action on the flash memory cell according to the third programming voltage V2. Step S425 performs a corresponding verification action on the flash memory cell according to the first verification voltage PV. Specifically, after a further programming action, a corresponding verification action is performed on the flash memory cell according to the first verification voltage PV, and used to verify whether the programming action of the flash memory cell has been completed. When all flash memory cells can pass the verification, the stylized action has been completed. In contrast, when not all flash memory cells can pass the verification (verification fails) (that is, the threshold voltage of the flash memory cells is not all greater than the first verification voltage PV), the index value m is incremented by 1 (step S427) , And under the condition that the index value m is not greater than the critical value M (step S429), steps S421, S423, and S425 are executed again.

FIG. 5 illustrates a block diagram of a flash memory storage device according to an exemplary embodiment of the invention. Please refer to FIG. 5, the flash memory device 500 of this embodiment includes a flash memory 510 and a controller 520. The flash memory 510 has a plurality of flash memory cells, and the controller includes a memory 521 and is coupled to the flash memory 510. When performing the operation flow of the above-mentioned embodiment in FIG. 3 and FIG. 4, after the highest threshold voltage RV and the second programmed voltage V1 are calculated, the highest threshold voltage RV and the second programmed voltage V1 can be stored in the memory 521 or flash memory 510. The controller 520 may also include an arithmetic operator, such as an adder. When the operation flow of the embodiment in FIG. 3 is performed as described above, the operation of step S317 may be performed through an arithmetic operator to directly calculate the second programmed voltage V1. In addition, corresponding to the operation flow of the embodiment of FIG. 4 of the present invention, the second programming voltage V1 is generated by gradual tracking based on the read step value, and it does not need to be generated by an arithmetic operator.

In addition, the flash memory 510 may be a NOR-type flash memory or a NAND-type flash memory. Moreover, the flash memory storage device 500 can be a memory card or a solid state drive (SSD), etc., and the flash memory device 500 can be set in a digital camera, a mobile phone, a music player, a tablet computer or a personal computer. In any electronic device such as a computer. The controller 520 may be a processor with computing capability. Alternatively, the controller 520 can be designed through a hardware description language (Hardware Description Language, HDL) or any other digital circuit design method known to those with ordinary knowledge in the art, and through a field programmable logic gate array ( Field Programmable Gate Array, FPGA), complex programmable logic device (Complex Programmable Logic Device, CPLD), or special application integrated circuit (Application-specific Integrated Circuit, ASIC) to implement hardware circuits such as test machines, Flash memory controller. The flash memory 510 may contain an arithmetic processor.

The implementation details of the programming actions of the flash memory device have been described in detail in the foregoing embodiments, and will not be repeated here.

In summary, the flash memory device provided by the present invention controls the distribution range of the threshold voltage of the programmed flash memory cell through multiple programming actions on the flash memory cell. In this way, a lower initial programming can be set, and the flash memory cell can be programmed by gradually adjusting the initial programming voltage, thereby optimizing the threshold voltage distribution of the programming memory cell. In addition, the present invention can program the flash memory cell by setting a lower initial programming action, so that the threshold voltage of the flash memory cell can be distributed in a preset voltage range. In this way, the uniformity of the electrical characteristics of the flash memory cell can be controlled, and the performance of the flash memory can be improved.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

Z0~Z3‧‧‧Programmed state RV0‧‧‧Initial read voltage Vstep‧‧‧Read step value RV1‧‧‧Read voltage RV‧‧‧Highest threshold voltage PV‧‧‧First verification voltage PV1 ‧‧‧Second verification voltage VTh‧‧‧Target threshold voltage OT‧‧‧Offset voltage value V0‧‧‧Initial programming voltage V1‧‧‧Second programming voltage V‧‧‧After third programming Voltage Vstep1‧‧‧Programmed step value S101~S111, S301~S331, S401~S429‧‧‧Programmed step 500‧‧‧Flash memory device 510‧‧‧Flash memory 520‧‧‧Control Device

FIG. 1 illustrates a flowchart of a programming method of a flash memory according to an exemplary embodiment of the present invention. 2A to 2C illustrate schematic diagrams of the threshold voltage distribution state of each programming action of the flash memory according to an exemplary embodiment of the present invention. FIG. 3 illustrates a flowchart of a programming method of a flash memory according to another exemplary embodiment of the present invention. FIG. 4 illustrates a flowchart of a programming method of a flash memory according to another exemplary embodiment of the present invention. FIG. 5 illustrates a block diagram of a flash memory storage device according to an exemplary embodiment of the invention.

S101~S111‧‧‧Programmed steps

Claims (6)

A programming method for flash memory includes: setting an initial programming voltage according to the process parameters of a plurality of flash memories, and performing a first programming on a plurality of flash memory cells according to the initial programming voltage Action; after the first programming action, detect the threshold voltage of the flash memory cells and obtain a maximum threshold voltage; set a target threshold voltage, based on the target threshold voltage, the initial programming voltage and the maximum Threshold voltage to generate a second programming voltage; performing a second programming action on the flash memory cells according to the second programming voltage; setting a first verification voltage after the second programming action , Performing a verification operation on the flash memory cells sequentially according to the first verification voltage, and performing an incremental operation according to a programming step value based on the second programming voltage to generate at least a third programming voltage; and Perform at least one third programming action on the flash memory cells according to the at least one third programming voltage, and set a second verification voltage. After each at least one third programming action, follow The second verification voltage performs a verification action on the flash memory cells, wherein after the first programming action, the step of detecting the threshold voltage of the flash memory cells and obtaining the highest threshold voltage includes: setting a The initial reading voltage and reading step value are based on the initial reading Voltage and integer multiples of the read step value to generate a plurality of read voltages; and sequentially perform read operations on the flash memory cells according to the read voltages to obtain the highest threshold voltage, wherein The target threshold voltage, the step of generating the second programmed voltage according to the target threshold voltage, the initial programmed voltage and the highest threshold voltage includes: after obtaining the highest threshold voltage, making the second programmed voltage equal to the The initial programmed voltage is added to the target threshold voltage and the highest threshold voltage is subtracted; or when the flash memory cells are read sequentially according to the read voltages, the second programmed voltage is synchronously made equal to The initial programming voltage plus the target threshold voltage minus the initial reading voltage and subtracting an integer multiple of the reading step value. The programming method of flash memory as described in item 1 of the scope of the patent application further includes: enabling the voltage values of the highest threshold voltage and the second programming voltage to be written to the flash memory or an external electron In the installation. According to the programming method of the flash memory described in claim 1, wherein after the second programming action, the method further includes: the first verification voltage can be greater than, less than or equal to the second verification voltage. A flash memory device includes: a flash memory having a plurality of flash memory cells; a controller, coupled to the flash memory, and used for: according to the process parameters of the flash memory Set the initial programming voltage, and perform a first programming action on the flash memory cells according to the initial programming voltage; after the first programming action, detect the threshold voltage of the flash memory cells And obtain a highest threshold voltage; set a target threshold voltage, generate a second programmed voltage according to the target threshold voltage, the initial programmed voltage, and the highest threshold voltage; flash the flashes according to the second programmed voltage The memory cell performs a second programming action; after the second programming action, a first verification voltage is set, the flash memory cells are verified sequentially according to the first verification voltage, and based on the The second programming voltage performs an incremental action based on a programming step value to generate at least one third programming voltage; and performing at least one third programming on the flash memory cells based on the at least one third programming voltage After each of the at least one third programming action, the flash memory cells are sequentially verified according to the second verification voltage, and a second verification voltage is set, wherein in the first programming After the operation, detect the flash memory cells In the operation of obtaining the highest threshold voltage, the controller sets an initial read voltage and a read step value, and the controller generates an initial read voltage and an integer multiple of the read step value A plurality of read voltages; and the controller sequentially performs a verification operation on the flash memory cells according to the read voltages to obtain the highest threshold voltage, wherein the target threshold voltage is set according to the target threshold voltage , The initial programming voltage and the highest threshold voltage to generate the second programming voltage: after the controller obtains the highest threshold voltage, the controller makes the second programming voltage equal to the initial programming voltage The target threshold voltage is added and the highest threshold voltage is subtracted, or, when the controller reads the flash memory cells sequentially according to the read voltages, the controller synchronizes the second program The conversion voltage is equal to the initial programming voltage plus the target threshold voltage minus the initial reading voltage and minus an integer multiple of the reading step value. The flash memory device described in claim 4, wherein the controller includes a memory, wherein the voltage values of the highest threshold voltage and the second programmed voltage are stored in the memory or the flash memory Body. According to the flash memory device described in claim 4, after the second programming operation, the first verification voltage can be greater than, less than or equal to the second verification voltage.

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