TWI422042B - Diode device and the fabrication method thereof - Google Patents

Description

Diode element and manufacturing method thereof

The present invention relates to a diode element and a fabrication technique thereof, and more particularly to a diode element structure based on an oxide film and a method of fabricating the same.

Due to the necessity of a high-temperature doping process, the conventional PN form of the diode is difficult to apply to applications such as a three-dimensional stacked integrated circuit requiring low process temperature and soft electronics. In addition, although the conventional oxide thin film diode has the advantage of low temperature process, its electrical characteristics such as forward current density and on-voltage are limited by the choice of materials, and cannot meet the needs of the industry. . For example, for a metal/N-type oxide/P-type oxide/metal MIIM (Metal/Insultor/Insultor/Metal) structure, the combination of two oxide films is quite specific; for metal/oxide/metal The MIM (Metal/Insultor/Metal) structure in which the combination of metal and oxide also requires a relatively specific material is sufficient to provide reasonable rectification characteristics. Therefore, the current stage of oxide diodes has not yet matured, and the technical problems such as complicated process and component characteristics have yet to be improved, in order to realize high-performance low-temperature process oxide thin film diodes.

In view of this, in an aspect of the present invention, a first embodiment provides a diode device including: a diode film having a first surface and a second surface, and including: a first conductive a region, providing a current density uniform current conduction, and the first conductive region component comprises a first oxide; and a second conductive region comprising a plurality of current channels to provide current conduction with non-uniform current density, and The composition of the current channel includes a second oxide; wherein the first oxide is different from the second oxide; and when a current is conducted between the first surface and the second surface, the second conductive region The DC current flowing through is greater than 10 times greater than the first conductive region; a first electrode is formed on the first surface; and a second electrode is formed on the second surface.

In another aspect of the present invention, a second embodiment provides a method of fabricating a diode element, comprising the steps of: providing a diode structure comprising: a diode film, which is subjected to a first oxidation The composition is composed of a first surface and a second surface; a first electrode is formed on the first surface; and a second electrode is formed on the second surface; and the first and second electrodes are Applying an electrical stress to the diode film to form a plurality of current channels in the diode film; wherein the current channel component comprises a second oxide, and the second oxide is different from the first Monooxide.

In still another aspect of the present invention, a third embodiment provides a method of fabricating a diode device, comprising the steps of: providing a diode film formed on a first electrode by a first oxide Applying a thermal annealing process to the diode film to form a plurality of current channels in the diode film; and forming a second electrode on the diode film; wherein the current channel component comprises a a second oxide, and the second oxide is different from the first oxide.

The features, objects, and functions of the present invention, as well as the technical means for achieving the same, are described in detail with reference to the accompanying drawings. It is understood that the scope and technical means of the invention are not limited thereby. In the description of the embodiments, the description of the "on" or "under" of each layer (film), region, pattern or structure formed on the substrate, layers (films), regions, spacers or patterns. The "upper" and "lower" systems include all direct or indirectly formed objects. In addition, the above or below each layer will be described based on the drawings. For the sake of convenience and clarity in the description, the thickness or size of each layer in the drawings is expressed in a rough, exaggerated or brief manner, and the dimensions of the constituent elements are not completely the actual size.

1 is a schematic structural view of a diode element according to a first embodiment of the present invention. The diode device 100 of the present embodiment includes a substrate 110, a first electrode 120, a second electrode 140, and a diode film 130. The diode film 130 is mainly composed of an oxide. The characteristic is that the current surface density transmitted by the cross section of the diode film 130 is not uniform, and can be divided into different conductive regions, or roughly classified according to the uniformity of the conducted current surface density: A conductive region 131 provides current conduction with uniform current density, and the second conductive region 132/133/134 provides current conduction with non-uniform current density, as shown in FIG.

The substrate 110 is generally a germanium wafer suitable for a semiconductor process. In this embodiment, a germanium wafer having deposited or epitaxial germanium oxide (SiO ₂ ) as an insulating layer is selected as the substrate 110, so that the diode element of the embodiment can be used. The semiconductor process is fabricated by a semiconductor process; but not limited thereto, the substrate 110 may also be a glass or a flexible substrate, depending on actual needs or subsequent component processes.

The first electrode 120 and the second electrode 140 are formed on both sides of the diode film 130 for providing electrical stress to the diode film 130 in the subsequent process of the embodiment, or as a The electrical signal external contact of the diode element 100. The composition of the first electrode 120 of the present embodiment is platinum (Pt), and the composition of the second electrode 140 is titanium (Ti) to provide good electrical and film properties; but not limited thereto, the first and second The composition of the electrode can also be selected from platinum, gold (Au), silver (Ag), lead (Pd), ruthenium (Ru), iridium (Ir), ruthenium oxide (RuO _x ), iridium oxide (IrO _x ), yttrium (Y). ), nickel (Ni), copper (Cu), titanium, tantalum (Ta), zinc (Zn), zirconium (Zr), hafnium (Hf), tungsten (W), chromium (Cr), indium tin oxide (ITO) Indium zinc oxide (IZO), aluminum oxide tin (ATO), and aluminum zinc oxide (AZO), or other conductive materials, depending on the actual conditions.

The diode-based film 130 composed of an oxide, the present embodiment is basically the choice of titanium dioxide (TiO ₂₎ film fabrication of the diode 130; on two considerations electrically polar substance, the relatively thin film diodes 130 The thickness is preferably between 1 nm and 1 μm, and the film actually produced in this embodiment has an average thickness of between 10 nm and 50 nm. It is to be noted that the composition of the diode film 130 is not limited to titanium dioxide, and may be titanium oxide (TiO _x ), tantalum oxide (TaO _x ), oxide (VO _x ), niobium oxide (NbO _x ), oxidation. Tungsten (WO _x ), zinc oxide (ZnO _x ), cadmium oxide (CdO _x ), yttrium oxide (HfO _x ), zirconia (ZrO _x ), nickel oxide (NiO _x ), copper oxide (CuO _x ), zinc oxide At least one of indium (InZn _x O _y ), and other similar oxide materials, depending on actual conditions or requirements of component characteristics, where x and y represent atomic percentages.

As described above, the current conducted by the diode film 130 is non-uniform throughout the cross section, and is classified as follows: Region 131 provides a low current conduction region with uniform current density, and second conductive region 132/133/134 provides a high current conduction region with non-uniform current density. The diode film 130 has a first surface 137 and a second surface 139. When a voltage is applied to the first electrode 120 and the second electrode 140, the first surface 137 and the second surface 139 are conductive. The current surface density between the second conductive regions is greater than 10 times greater than the first conductive region, and also exhibits the electrical characteristics of the components of the diode. It should be noted that the second conductive region 132/133/134 may contain a plurality of current channels different from the original titanium dioxide or oxide, resulting in uneven density of the conduction current. For example, the first conductive region 131 is composed of titanium dioxide or oxide (referred to as a first oxide) that originally forms the diode film 130, and the current path included in the second conductive region 132/133/134 The composition is a titanium oxide or an oxide (referred to as a second oxide) different from the first oxide. The second oxide may also cause the oxygen content in the first oxide to be lost during the fabrication or processing of the diode film 130 to form the same chemical composition element as the first oxide. But similar materials with different atomic percentages of oxygen content. In addition, the diode film is not limited to the structure of a single layer film, and may be a multilayer oxide film or an additional oxide film between the diode film 130 and the second electrode 140.

3 is a schematic cross-sectional view of the current channel structure. As shown in FIG. 3, the structure of the current channel may be an elongated cylindrical channel substantially perpendicular to the first or second surface 137/139 and have different states, for example, the current channel 160 extends through the diode. The film 130 and the current channel 161/162/163 do not completely penetrate the diode film 130; but the current channel 160/161/162/163 The composition of the oxide within may be different from the composition of the diode film 130 outside the current path.

The following examples illustrate the method of producing the diode element of the present invention. 4 is a schematic flow chart of a manufacturing method according to a second embodiment of the present invention. Referring to FIG. 1 together, the manufacturing method 200 of the embodiment includes the following steps: Step 210, providing a diode structure includes: a diode film 130, which is composed of a first oxide and has a first a surface 137 and a second surface 139; a first electrode 120 is formed on the first surface 137; and a second electrode 140 is formed on the second surface 139. In step 220, an electrical stress is applied to the diode film 130 by the first and second electrodes 120/140 to form a plurality of current channels in the diode film 130. Wherein the composition of the current channel comprises a second oxide, and the second oxide is different from the first oxide; or the first and second oxides have the same chemical composition element, but different oxygen content atoms percentage. Related technical features of the first electrode 120, the second electrode 140, the diode film 130, and the current path are described in the description of the first embodiment above, and are not described herein again.

For the applied electrical stress of step 220, it may be selected from a constant DC voltage bias (DC), a DC voltage Sweep, a constant DC current, and a DC current Sweep. And the AC voltage pulse, etc., can all be used to manufacture the diode components of the cost embodiment. As an example of an actual fabrication experiment, the second embodiment uses a DC bias voltage to apply a DC voltage of 3 V to the first and second electrodes 120/140 for about 5 seconds; but the above voltage and application time Use is not for this Alternatively, the DC voltage between 0.5V and 50V may be applied for less than 10 seconds, depending on the material and actual thickness of the diode film 130.

Referring to FIG. 5, it is a schematic flowchart of a manufacturing method according to a third embodiment of the present invention. Referring to FIG. 1 together, the manufacturing method 300 of the embodiment includes the following steps: Step 310, providing a diode film 130 formed on a first electrode 120 by a first oxide; and step 320, applying a a thermal annealing process is performed on the diode film 130 to form a plurality of current channels in the diode film 130; and in step 330, a second electrode 140 is formed on the diode film 130; The component of the current channel comprises a second oxide, and the second oxide is different from the first oxide; or the first and second oxides have the same chemical composition element, but different atomic percentages of oxygen content . For the thermal annealing process of step 320, a conventional process such as rapid thermal annealing or multi-stage thermal annealing may be selected, and the fabrication of the diode element of the embodiment can be achieved. The thermal annealing temperature is preferably less than 800 ° C, and is not limited thereto. The temperature, stage, and application time required for thermal annealing depend on the material and actual thickness of the diode film 130. Related technical features of the first electrode 120, the second electrode 140, the diode film 130, and the current path are described in the description of the first embodiment above, and are not described herein again.

The current-voltage characteristics of the diode film 130 before and after the electrical stress or thermal annealing process are quite different. This can be seen from the current-voltage curve (IV curve) experimental measurement chart of FIG. 6: the two poles The forward current 610 and the reverse current 620 of the bulk film after the electrical stress or thermal annealing process are greater than the forward current 630 and the reverse current 640 before the electrical stress or thermal annealing process, and the current-voltage curve has two The electrical characteristics of the components of the polar body.

Please also refer to FIG. 2 and FIG. 3 again, and note that the formation of the second conductive region 132/133/134 and the internal current channel 161/162/163 thereof is caused by electrical stress or thermal annealing in the fabrication process, which The formation of the second conductive region 132/133/134 and its internal current channel 161/162/163 is not specific and fixed in number, shape, or position, depending on the actual situation at the time of manufacture, but substantially Thereby the electrical properties of the diode element are achieved. In addition, measuring the surface conductivity of the diode film by conducting atomic force microscopy (Conductive AFM) helps to detect the formation of the second conductive region 132/133/134 and its internal current channel 161/162/163. FIG. 7 is a surface conductivity measurement diagram of a sample of a diode element fabricated according to a second embodiment of the present invention, wherein a region having a higher current density (or a lighter chromaticity) may be regarded as a second conductive region. It also presents an irregular distribution pattern.

The above description includes the features, structures, and other similar effects, which are merely preferred embodiments of the present invention, and the scope of the present invention is not limited thereto. In addition, the features, structures, and other similar effects shown in the above embodiments may be equally modified and modified by those skilled in the art in accordance with the scope of the present invention, and the meaning of the present invention will remain. Further, the present invention should be considered as further implementations of the present invention without departing from the spirit and scope of the invention.

Moreover, the embodiments described above are merely exemplary embodiments and are not intended to limit the scope of the invention. For example, the elements or units used in the various embodiments can be modified and implemented by those skilled in the art, without departing from the scope of the invention.

100. . . Diode component

110. . . Substrate

120. . . First electrode

130. . . Diode film

131. . . First conductive area

132/133/134. . . Second conductive area

137. . . First surface

139. . . Second surface

140. . . Second electrode

160/161/162/163. . . Current channel

200. . . Production Method

210/220. . . step

300. . . Production Method

310/320/330. . . step

610. . . Forward current curve of diode film after electrical stress or thermal annealing

620. . . Reverse current curve of diode film after electrical stress or thermal annealing

630. . . Forward current curve of diode film before electrical stress or thermal annealing

640. . . Reverse current curve of diode film before electrical stress or thermal annealing

Fig. 1 is a schematic view showing the structure of a diode element according to a first embodiment of the present invention.

Figure 2 is a schematic view of a conductive region on a cross section of a diode film.

Figure 3 is a schematic cross-sectional view of the current channel structure.

4 is a schematic flow chart of a manufacturing method according to a second embodiment of the present invention.

FIG. 5 is a schematic flow chart of a manufacturing method according to a third embodiment of the present invention.

Fig. 6 is a graph showing the current-voltage curve of the sample of the diode of the present embodiment.

Figure 7 is a graph showing the surface conductivity of a sample of a diode of this embodiment.

100. . . Diode component

110. . . Substrate

120. . . First electrode

130. . . Diode film

137. . . First surface

139. . . Second surface

140. . . Second electrode

Claims (20)

A diode device comprising: a diode film having a first surface and a second surface, and comprising: a first conductive region, providing current conduction with uniform current density, and the first conductive region The composition comprises a first oxide; and a second conductive region comprising a plurality of current channels, providing current conduction with non-uniform current density, and the composition of the current channel comprises a second oxide; wherein the first The oxide is different from the second oxide; when a current is conducted between the first surface and the second surface, the DC current flowing through the second conductive region is greater than 10 times greater than the first conductive region a first electrode formed on the first surface; and a second electrode formed on the second surface. The dipole element of claim 1, wherein the first and second oxides have the same chemical composition element, but different atomic percentages of oxygen content. The diode element of claim 1, further comprising an oxide film formed between the second surface and the second electrode. The diode element of claim 1, wherein the thickness of the diode film is between 1 nm and 1 μm. The dipole element of claim 1, wherein the first and second oxides comprise at least one of the following oxides: titanium oxide (TiO _x ), tantalum oxide (TaO _x ), oxide (VO _x ), oxidation Niobium (NbO _x ), tungsten oxide (WO _x ), zinc oxide (ZnO _x ), cadmium oxide (CdO _x ), hafnium oxide (HfO _x ), zirconium oxide (ZrO _x ), nickel oxide (NiO _x ), copper oxide (CuO _x ), indium zinc oxide (InZn _x O _y ), and analogs thereof; wherein x and y represent atomic percentages. The dipole element of claim 1, wherein the components of the first and second electrodes comprise at least one of the following conductor materials: platinum (Pt), gold (Au), silver (Ag), lead (Pd), bismuth (Ru), iridium (Ir), yttrium oxide (RuO _x ), yttrium oxide (IrO _x ), yttrium (Y), nickel (Ni), copper (Cu), titanium (Ti), tantalum (Ta), zinc ( Zn), zirconium (Zr), hafnium (Hf), tungsten (W), chromium (Cr), indium tin oxide (ITO), indium zinc oxide (IZO), aluminum oxide tin (ATO), and aluminum zinc oxide (AZO) ). A method for fabricating a diode element, comprising: providing a diode structure comprising: a diode film composed of a first oxide and having a first surface and a second surface; a first electrode is formed on the first surface; and a second electrode is formed on the second surface; and an electrical stress is applied to the diode film by the first and second electrodes to form a plurality of And a current channel in the diode film; wherein the component of the current channel comprises a second oxide, and the second oxide is different from the first oxide. The method of claim 7, wherein the first and second oxides have the same chemical composition element, but different atomic percentages of oxygen content. The method of claim 7, wherein the method of applying electrical stress is selected from the group consisting of a DC bias voltage, a DC voltage sweep, a DC bias current, a DC current sweep, and an AC voltage pulse. The method of claim 8, wherein the DC bias voltage is between 0.5V and 50V and the applied time is less than 10 seconds. The method of claim 7, wherein the forward and reverse currents of the diode film subjected to the electrical stress are greater than the forward and reverse currents before the electrical stress is not affected. The method of claim 7, wherein the diode film has a thickness of between 1 nm and 1 μm. The method of claim 7, wherein the first and second oxides comprise at least one of the following oxides: titanium oxide (TiO _x ), strontium oxide (TaO _x ), oxide (VO _x ), cerium oxide ( NbO _x ), tungsten oxide (WO _x ), zinc oxide (ZnO _x ), cadmium oxide (CdO _x ), hafnium oxide (HfO _x ), zirconium oxide (ZrO _x ), nickel oxide (NiO _x ), copper oxide (CuO) _x ), indium zinc oxide (InZn _x O _y ), and analogs thereof; wherein x and y represent atomic percentages. The method of claim 7, wherein the composition of the first and second electrodes comprises at least one of the following conductor materials: platinum (Pt), gold (Au), silver (Ag), lead (Pd), ruthenium (Ru) ), iridium (Ir), yttrium oxide (RuO _x ), yttrium oxide (IrO _x ), yttrium (Y), nickel (Ni), copper (Cu), titanium (Ti), tantalum (Ta), zinc (Zn) Zirconium (Zr), hafnium (Hf), tungsten (W), chromium (Cr), indium tin oxide (ITO), indium zinc oxide (IZO), aluminum oxide tin (ATO), and aluminum zinc oxide (AZO). A method of fabricating a diode element, comprising: providing a diode film formed on a first electrode by a first oxide; applying a thermal annealing process to the diode film to form a plurality of a current channel in the diode film; and forming a second electrode on the diode film; wherein the current channel component comprises a second oxide, and the second oxide is different from the first Oxide. The method of claim 15, wherein the first and second oxides have the same chemical composition element, but different atomic percentages of oxygen content. The method of claim 15, wherein the temperature of the thermal annealing process is lower than 800 °C. The method of claim 15, wherein the forward and reverse currents of the diode film subjected to the thermal annealing process are greater than the forward and reverse currents before the thermal annealing process. The method of claim 15, wherein the diode film has a thickness of between 1 nm and 1 μm. The method of claim 15, wherein the first and second oxides comprise at least one of the following oxides: titanium oxide (TiO _x ), tantalum oxide (TaO _x ), oxide (VO _x ), cerium oxide ( NbO _x ), tungsten oxide (WO _x ), zinc oxide (ZnO _x ), cadmium oxide (CdO _x ), hafnium oxide (HfO _x ), zirconium oxide (ZrO _x ), nickel oxide (NiO _x ), copper oxide (CuO) _x ), indium zinc oxide (InZn _x O _y ), and analogs thereof; wherein x and y represent atomic percentages.