阅读说明：本技术 Dram氧化物电极、dram及其应用 (DRAM oxide electrode, DRAM and application thereof ) 是由 徐光伟 熊文豪 龙世兵 赵晓龙 白卫平 于 2020-06-15 设计创作，主要内容包括：一种DRAM氧化物电极、DRAM及其应用,该氧化物电极采用的材料包括RuO<Sub>x</Sub>、IrO<Sub>x</Sub>、PdO<Sub>x</Sub>、PtO<Sub>x</Sub>、AgO<Sub>x</Sub>、AuO<Sub>x</Sub>、Ga<Sub>2</Sub>O<Sub>3</Sub>中的任一种或多种组合。本发明针提出新的电极材料,包括高功函数的金属氧化物电极RuO<Sub>x</Sub>、IrO<Sub>x</Sub>、PdO<Sub>x</Sub>、PtO<Sub>x</Sub>、AgO<Sub>x</Sub>和AuO<Sub>x</Sub>,以及金属氧化物半导体Ga<Sub>2</Sub>O<Sub>3</Sub>；本发明氧化物电极与氧化物介电材料结合界面更好,可以减少缺陷和抑制低介电层的形成,进一步降低漏电和提高电容密度。(DRAM oxide electrode, DRAM and application thereof, wherein the oxide electrode adopts materials including RuO x 、IrO x 、PdO x 、PtO x 、AgO x 、AuO x 、Ga 2 O 3 Any one or more combinations thereof. The present invention is directed to novel electrode materials, including high work function metal oxide electrodes RuO x 、IrO x 、PdO x 、PtO x 、AgO x And AuO x And metal oxide semiconductor Ga 2 O 3 (ii) a The oxide electrode and the oxide dielectric material have better bonding interface, can reduce defects and inhibit the formation of a low dielectric layer, further reduces electric leakage and improves capacitance density.)

1. A DRAM oxide electrode is characterized in that the oxide electrode adopts a material comprising RuO_x、IrO_x、PdO_x、PtO_x、AgO_x、AuO_x、Ga₂O₃Any one or more combinations thereof.

2. A DRAM having the DRAM oxide electrode of claim 1 incorporated therein.

3. Use of a DRAM oxide electrode according to claim 1 or a DRAM according to claim 2 in the field of memories.

Technical Field

The invention belongs to the field of memories, and particularly relates to a DRAM (dynamic random access memory) oxide electrode, a DRAM and application thereof.

Background

With the development of big data, cloud computing, internet of things, AI, etc., the role played by memory in the entire industry chain is becoming more important. From the prior computer system structure, the memory is divided into cache, internal memory and external memory. DRAM (dynamic random access memory) has small volume, high integration level, low power consumption and higher speed than all ROM: (Read only memory) is fast and, in addition, its price is much cheaper than SRAM (static random access memory), and therefore, it is always a better choice for memory. DRAMs have been using 1T1C (one transistor and one capacitor) structures for decades, with field effect transistors being commonly used for transistors, and capacitors having SIS (semiconductor/insulator/semiconductor), MIS (metal/insulator/semiconductor), and MIM (metal/insulator/metal) structures. With the continuous improvement of integration level and performance, the capacitor material in 1T1C has undergone multiple evolutions, from the initial SiO₂SIS capacitors formed of dielectric layers and polysilicon electrodes have been developed to the present day ZAZ (ZrO)₂And Al₂O₃Stack) dielectric material and TiN electrode. To obtain higher performance DRAMs, the introduction of new materials is essential.

Currently, maintaining a sufficiently large capacitance and a sufficiently low leakage current are essential conditions for proper operation of the DRAM. As the feature size and plate area of capacitors continue to decrease as integration increases, thinner or/and higher dielectric constant dielectric materials must be used to increase the capacitor density. The existing electrode material is limited by the characteristics of the electrode material, the work function is not high enough, the height of a potential barrier with a dielectric material, particularly an ultrahigh dielectric material is not large enough, and a contact interface is not optimal, so that the leakage current is increased, the capacitance density is reduced, and the performance and the normal work of the DRAM are influenced.

There are several requirements for DRAM capacitor material selection. For the dielectric material, as the size of DRAM is gradually reduced, the dielectric material needs to be thinner and the dielectric constant needs to be larger under the requirement of ensuring a sufficiently large capacitance value; for the electrode material, in order to ensure a sufficiently low leakage current of the capacitor, a high work function electrode material is required to increase the potential barrier between the electrode material and the dielectric layer. Meanwhile, in order to ensure the access speed of the DRAM to the memory cell, the electrode material needs to have lower resistivity. With decades of development, ZAZ (ZrO) is a common dielectric material₂And Al₂O₃Stack), the electrode material is TiN, wherein the TiN electrode material has a work function of about 4.5-4.7 eV. As DRAMs evolve into new technology nodes, the capacitance size further shrinks, the demand for capacitance density further increases, and thinner features must be employedAnd/or higher dielectric constant (typically lower bandgap), TiN electrodes will have difficulty meeting low leakage requirements and therefore require higher work function electrodes to replace.

For the leakage situation of the capacitor under the smaller size of the DRAM, the following requirements are required for the selection of the capacitor electrode material: to ensure that the leakage is within an acceptable range, new electrode materials require higher work functions, higher barrier formation with dielectric materials, and better contact interfaces. To ensure the operating frequency of the DRAM, the resistance of the new electrode material cannot be too large.

Disclosure of Invention

It is therefore one of the objectives of the claimed invention to provide a DRAM oxide electrode, a DRAM and applications thereof, which are intended to at least partially solve at least one of the above-mentioned problems.

To achieve the above objects, as one aspect of the present invention, there is provided a DRAM oxide electrode using a material including RuO_x、IrO_x、PdO_x、PtO_x、AgO_x、AuO_x、Ga₂O₃Any one or more combinations thereof.

As another aspect of the present invention, there is also provided a DRAM having the DRAM oxide electrode as described above incorporated therein.

As a further aspect of the invention there is also provided a DRAM oxide electrode as described above or a DRAM as described above for use in the memory field.

Based on the above technical solutions, the DRAM oxide electrode, the DRAM and the application thereof of the present invention have at least one of the following advantages over the prior art:

the present invention is directed to novel electrode materials, including high work function metal oxide electrodes RuO_x、IrO_x、PdO_x、PtO_x、AgO_xAnd AuO_xAnd metal oxide semiconductor Ga₂O₃(ii) a The oxide electrode has better bonding interface with the oxide dielectric material, can reduce defects and inhibit the formation of a low dielectric layer, further reduces electric leakage and improves capacitanceDensity.

Drawings

FIG. 1 is a diagram of a capacitor band diagram of zirconium dioxide in a non-operating state according to an embodiment of the present invention;

FIG. 2(a) is a band diagram of a zirconium dioxide capacitor in an embodiment of the present invention;

FIG. 2(b) is a diagram illustrating the principle of direct tunneling when a zirconium dioxide capacitor is in an operating state according to an embodiment of the present invention;

FIG. 2(c) is a schematic diagram of F-N tunneling when a zirconium dioxide capacitor is in an operating state according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of leakage caused by P-F emission or TAT when a zirconium dioxide capacitor actually works according to an embodiment of the present invention;

FIG. 4(a) is a band diagram of zirconium dioxide with a reduced physical thickness in an operating state according to an embodiment of the present invention;

FIG. 4(b) is a band diagram of the new material with higher dielectric constant, smaller forbidden band and lower barrier height in the working state of the present invention;

FIG. 5(a) is a diagram of a band diagram of direct tunneling electron after the thickness of zirconium dioxide is reduced in an embodiment of the present invention;

FIG. 5(b) is a diagram of an F-N tunneling band of electrons after the thickness of zirconium dioxide is reduced in an embodiment of the present invention;

FIG. 5(c) is a schematic diagram of leakage caused by P-F emission or TAT in actual operation of a new material with higher dielectric constant, smaller forbidden band and lower barrier height according to an embodiment of the present invention;

FIG. 6(a) is a band diagram of a thin zirconium dioxide practical working with a new electrode material in an embodiment of the present invention;

fig. 6(b) is a band diagram of a new material with a higher dielectric constant, but a smaller forbidden band and a lower barrier height using the new electrode material in an embodiment of the present invention in actual operation.

Detailed Description

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.

The invention discloses a DRAM oxide electrodeThe oxide electrode is made of RuO_x、IrO_x、PdO_x、PtO_x、AgO_x、AuO_x、Ga₂O₃Any one or more combinations thereof.

The invention also discloses a DRAM, which contains the DRAM oxide electrode.

The invention also discloses the application of the DRAM oxide electrode or the DRAM in the field of memories.

The technical solution of the present invention is further illustrated by the following specific embodiments in conjunction with the accompanying drawings. It should be noted that the following specific examples are given by way of illustration only and the scope of the present invention is not limited thereto.

The DRAM electrode material comprises a high-work-function metal oxide electrode RuO_x(rubidium oxide) IrO_x(Iridium oxide), PdO_x(Palladium oxide), PtO_x(platinum oxide), AgO_x(silver oxide) and AuO_x(gold oxide), and metal oxide semiconductor Ga₂O₃。