TW550761B - Method for operating an NROM device - Google Patents

Abstract

The present invention provides a method for operating an NROM device, where the source and drain are surrounded by a heavy doping. When programming the NROM device, a more positive source bias and a more negative substrate bias is used to increase the body effect of the substrate for reducing the current require for channel hot electron injection (CHEI) programming. Furthermore, before erasing the NROM array, a pre-programming operation is performed to program every single memory cell of the NROM array to the written state for preventing over-erasing of the memory cells.

Description

550761 V. Description of the invention (1) The present invention is based on a method of operating a read-only memory element, and does not include a silicon nitride read-only memory element (nitride read, memory Je'ce, abbreviated as CaiM) device). The current read-only memory of nitrided stone Xiuyu is a stacked structure composed of oxide stone / nitrided stone / oxided stone (〇N〇) composite layer as the electrical 3 sink layer, and the silicon oxide / The silicon nitride / silicon oxide (0N0) layer has interlayers, and there are adjacent Toyo, store /, and &100; poles in the substrate. The material is mainly Ϊ because the charge is trapped in the layer. 'So this kind of electrically erasable and programmable read-only record: the external lofc rically erasable programmable ROM (also known as the ratified silicon read-only memory (NROM). In particular, because the nitrided layer has no ability to capture the electrons in the charge layer, the silicon nitride is injected into the local area of the nitrogen-cut layer and the electrons are only concentrated on the lice when the element is programmed. Silicon read-only memory partially stores the local memory of J 1 near the source or drain. Therefore, the voltage applied by changing the p q} region can be in a single nitride: J source / drain :, single-group electrons or no electrons. Because: No. 2 is written in two groups of electricity ;: To write in a single-memory cell T read-only memory :: Yuan (= ",) flashing = a single record t will gradually shrink, resulting in Silicon nitride only "gate line width: Questions, such as the occurrence of stylized operation on the operation of ^ ^ ΐ ;: r: slng) ^ ^ ^ ^ ^ ^ a Λ Λ ρ sex injection hole ( hQle), You μ㈣ wiped Λ multiple times

cS713twf .ptcj 550761 V. Description of the invention (2) Because a large number of holes are accumulated above the source or non-electrode, there will be a serious leakage of electrons from another bit using the same bit line or word line Occurs, especially at high temperatures. This is the so-called "over-erase ((^ 61 * _61 ^^)". Moreover, the initial voltage is reduced or the channel length is called "channel" After shortening, the above situation will become more serious. Therefore, the object of the present invention is to provide a method for operating a silicon nitride read-only memory element to prevent a large number of holes accumulated above the source or drain from affecting adjacent ones. Another bit of electrons causes a serious leakage. Another object of the present invention is to provide a method for operating a silicon nitride read-only memory element, which can avoid excessive erasure. Another object of the present invention is to provide a nitrogen The operation method of the silicon read-only memory element can reduce the current programmed as a channel hot electron injection (channei hQt electron injection (CHEI) for short.) According to the above and other purposes, The invention proposes an operation method of a nitrogen & silicon read-only memory element, which is provided around a source / drain with a heavily doped base j. When the silicon nitride read-only memory is programmed, a correction is used. More positive source bias or a more negative substrate bias [: (factory: ㈣ive substrate bias), which increases the substrate effect by 0 ye feet) and reduces the injection of hot electrons as channels: "outside" in Prior to erasing the nitride read-only memory array, a pre-programining operation (pre-programining 〇perati〇n) was performed to cut all the memory cells in the read-only memory array into a written state. ) To prevent over-erase.

8713twf.ptd Page 6 550761 V. Description of the invention (3) The invention is based on the source / drain cycle: it increases the performance of programming. And in the garden? -Heavy doped substrate '= is a negative substrate bias, the positive source bias as the channel hot electron injection (CHEI) 9 force, the bottom effect, so you can reduce the erasing Before, Luo # — 'the current. In addition, the present invention / above the drain,? = Pre & type operation, so it can avoid serious t-degree erasure at the source. Bu; further prevent the silicon nitride read-only memory element from being described as follows: ♦ 軚 軚 Example of yoke, and in accordance with the attached drawings, make detailed labeling description: ίο · Provide a nitride nitride read-only Memory element, where a heavily doped substrate is provided at the source / periphery 2 0: Increase substrate effect 3 0: Pre-programmed before erasing 21 0: Increase source bias voltage 220: Increase substrate negative bias This embodiment mainly uses a silicon nitride read-only memory device (NROM device) as an example, and as the device continues to shrink, the execution of the silicon nitride read-only memory device is programmed. The mechanism is mainly based on the channel hot electron injection (CHEI) method, and the operation steps are as follows: 8713twf.ptd page 7 550761

As shown. FIG. 1 is a flowchart showing the operation flow of a silicon nitride read-only memory device (NROM device) according to a preferred embodiment of the present invention. shell. Please refer to FIG. 1. In step 10, a silicon nitride read-only memory element is provided, wherein a heavily doping substrate is provided around the source / drain. Since one of the objectives of the present invention is to reduce the programming current, the reduction of the programming current will affect the programming efficiency. Therefore, it is necessary to make the substrate around the source / dim electrode a heavily doped substrate; that is, to increase the doping concentration of the substrate around the source / dim electrode to increase the programming efficiency and increase the substrate doping. The concentration method is, for example, using a ceH implantation process or a pocket ion implantation process. Then, in step 20, the base effect (b o d y e f f e c t) is increased. Because the channel thermal electron injection (CHEI) is used to program the silicon nitride read-only memory element, 'increasing the substrate effect is a method to effectively reduce the required channel hot electron injection (CHEI) program current. For example, the method of increasing the base effect can utilize a corrected source bias (111〇]: 6 poSitiVe source bias), as in step 21, increasing the source bias (Vs); or With more negative substrate bias, as in step 220, the substrate negative bias (| VB |) is increased. Thereafter, in step 30, pre-programming is performed before erasing. This is to eliminate the over-erase problem, and the injected holes i I 1 are compensated electronically. 1 I! 11 1 I! ISI 1 8713twf.ptd Page 8 550761 V. Description of the invention (5) (in jected hole). Therefore, all of the = Memory: 成 = stylized nitrogen state (array) in the siliconized read-only memory array are being wiped. The pre-programmed wind is written in the form of channel hot electron injection (CHEI), which can also be performed by F_N = not only by tunnel ing) or any other mechanism by electron injection. Table 1 shows the comparison between the conventional method ρ and the operation method of the silicon read-only memory element. And the nitrogen of the present invention.

Bu — ______ — 丄 Conventional method I The present invention 丨 I Memory cell initial voltage (volts) I! — — Η 1 丄 · d I 2 · 5 I Bu--+ 丨 stylized V g (volts) 丨 Bu —---—— + 丨 stylized Vd (volt) t ^ 丨 6 ^ ~ — —I ----— + —— L — (volt) I 0 | 1 2 2;, ----— ( ------ ^ 程 — 式 —Ή 二 公 A) 丄 350 ~ 4 ° 0 I 5◦ ~ 1. 〇1 Still, as can be seen from the table, the present invention increases the source bias voltage (Vs), ρα obtains more conventional formulas, spheroids, and a ^ ^ vs; you can use the method and the present invention to prepare a, 1 clothes One 疋 疋 knowledge k operation method of V-Master memory element --1-- ~ ---- 9 ~ 1 1 + one --- 1 ---- 5. Description of invention (6) Comparison Chart. Table 2 Current

Ding — Γ The number of memory cells I I ----- 1 ~ —__ time

| 知 知 | 5 0 0 # A l ·, _ ——— —- I _ '-Ding — I This invention I 100 # A + 丄 + ---- 4 Η + ——— 20 Η Μ seconds Although Mao Yue ..., the number of memory cells that requires more time to write in the known works is much larger than that in the first knowledge = because the description of the mother ~ body concept still has higher operating efficiency than the known ones. Therefore, the features of the present invention include ： 哝 i ::: t The substrate around the source / drain has an increased doping = When the current is reduced, the device will not be stylized. &Amp; s i2 7 in stylized nitride Use a more positive source bias or dynamics when reading the memory element; a negative substrate bias from Mi ^ ^ ^ ^ to increase the substrate effect and a 3-channel hot electron injection (CHEI) stylized current. Before the erasing, we performed a pre-programmed operation to prevent erasure: the state of the bit write 'so the electrons of another bit can be avoided, and a large number of holes affect the neighboring Serious leakage to the house. "By changing the bias acting on the gate, source / drain, and substrate 550761. 5. Description of the invention (7) pressure to increase the substrate effect, and pre-programmed before erasing, so it can Under the trend of technological development, at the same time prevent excessive erasure and improve the programming performance of components. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

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Claims (1)

550761 Patent application scope ^ 1 · A method for operating a silicon nitride read-only memory element, suitable for operating a gaseous stone read-only memory device, the nitride-ready read-only memory device includes a source, a drain, And—a substrate, wherein the substrate has an increased doping concentration around the source and the drain, the steps include: increasing the substrate effect to reduce a required channel hot electron injection (CHEI) stylized current, wherein The substrate effect is increased by changing the bias applied to the gate, the source, the drain, and the substrate; and a pre-programming is performed before erasing to program the All memory cells become written. ° Si 70 2 · The method of operating a silicon nitride read-only memory element as described in item 1 of the scope of the patent application, wherein the step of increasing the base effect includes using a source of 2 π solitary 黻 η leveling. 3 · If a patent is applied for The method for operating a silicon nitride read-only memory cell as described in the first item of the scope, wherein the step of increasing the base effect includes the use of a candid bias. Ping Anbei ’s base read-only memory element includes F-N tunneling effect. The read-only memory element includes electron injection. 5. Nitriding operation method as described in item 丨 of the patent application scope, in which the The pre-programmed method should be 0. The nitriding operation method as described in item 1 of the scope of patent application, wherein the pre-programmed method is implemented. 8713twf.ptcl Page 13 550761 VI. Application scope of patents ^ Nitrogen-cut read-only as described in item 1 of the% patent scope > _ 2 Α M 1, where the formula of the increased doping degree ,, € ^ 7 recall 7 ^ pieces of memory cell ion implantation system ^ I million must include Sakata ^ S a # ^ and the use of pocket-type ion implantation process 8 · a kind of nitride stone Xiqi Qianqi & -· ,, of —. Silicon nitride read-only memory element η: The operation method of 70 pieces, which can be used as a pole. The steps include: ”° Below, the element includes a source, one of which is increased by increasing the bias voltage of the source. = Hot! Sub-injection (CHEI) stylized current in the two requirements: pre-programmed to program all the memory cells of the nitride stone memory cell 仟 into a written state. Find as 9 · 方 如Λ Please Λ Li Fan, enumerating the pre-programmed ^ (chei ^) element of the nitride nitride device described in item 8 The method of preprogramming includes channel hot electron annotation if The operation method of the silicon nitride read-only memory device described above, in which the method of performing the pre-programming includes the FN tunneling effect. 11. · The nitride nitride read-only memory as described in the eighth patent application The operation method of the device, which implements the mechanism of the pre-programmed method with an electron injection method. # 1 2 · —A method of operating a gaseous stone Xiu read-only memory device, suitable for operating a nitrided Xiu Xiu memory device, The nitride read-only memory device includes a substrate, and the steps include: Increasing the substrate effect by increasing the negative bias of the substrate to reduce the channel hot electron injection (C Ε EI) stylized current of the product; and 8713twf.ptd Page 14 550761 6. Scope of patent application ~ A pre-form is performed before erasing to program all the memory tires in the part # ^ At x emulsified silicon memory cell 13. If you apply for a special VI to become a written state sad. ! 4. If the operation method of the patent application is applied, Fu Ye should also read the Emulsified Silicone in the K project. The method of implementing this pre-programming includes F_Nf 1 5 · If applying for a special;-operation method, which includes a read-only note of silicon nitride as described in item 12; mode mechanism. 2. The method for carrying out the pre-programming includes a method of operation, which is implanted from the silicon nitride read-only memory element 々 (CHEI) described in item 12. The method of performing this pre-programming includes the channel potential component A