TWI558985B - Optoelectronic device for light sensor and manufacturing method thereof - Google Patents

Description

Photoelectric element for photosensor and manufacturing method thereof

The present invention relates to a photovoltaic element for a photosensor, and more particularly to a photovoltaic element having a barrier region.

In optical applications, light from various wavelengths of the external light source is often used for various types of applications, such as a visible light sensor with a sensing wavelength of 380 nm to 760 nm, or an infrared sensation with an infrared wavelength range. The detector, the ultraviolet sensor in the ultraviolet range, the light sensor that emits a wavelength of light and receives the light signal reflected by the wavelength of the light to achieve the distance measurement purpose and the sensor of the optical fiber optical signal transmission, etc. A light sensing device to which an external light source is applied to convert an optical signal into an electrical signal. Generally speaking, in the field of photosensors, it can be mainly divided into two major units, a transistor and a diode. The principle of operation is that external light is irradiated to the diode to generate a current, and the output current thereof is re The transistor disposed through the rear portion of the diode is amplified to a multiple of several times to generate a stronger signal. However, due to the electrical characteristics of the diode and the electrical connection structure of the photosensor, leakage current leaks from the diode to the transistor and the output quality is degraded. Therefore, in the structure of the conventional photo sensor, there is an improvement. The method of pole leakage current. Conventionally, the method of improving the leakage current of the diode is usually deposited on the diode by chemical vapor deposition of a yttrium oxide (SiOx) insulating film layer. However, in this way, the overall process of the photosensor is increased. Add one Chemical vapor deposition causes an increase in the process.

In view of the above, in the field of sensor technology, a chemical vapor deposition process is added to the overall process to deposit a yttrium oxide (SiOx) film to prevent leakage current. In this process, a yttrium oxide film is deposited after deposition of yttrium oxide. By oxidizing the yttrium oxide film, this step may further damage the originally deposited diode when the photoresist is finally etched. Therefore, although the conventional technology improves the leakage current problem, it increases the process of the photo sensor, and the increased process is more likely to damage the existing diode structure, thereby affecting the yield.

In view of this, the inventor of the present invention has proposed a novel photovoltaic element structure for a photosensor and a method of fabricating the same, which is oxidized after the patterning step in the process of patterning the diode. The surface is such that a yttrium oxide (SiOx) layer is formed on the side surface of the diode, which can effectively improve the leakage current of the diode, so that it is not necessary to add a new step to make the yttrium oxide layer, and also avoids The polar body is at risk of damage, which in turn can maintain the original high yield.

It is an object of the present invention to provide a photovoltaic element for a photosensor that improves leakage current generation in a photosensor by providing a barrier region.

An object of the present invention is to provide a photovoltaic element for a photosensor and a method for fabricating the same, which can oxidize sidewalls of a semiconductor layer to form a barrier region by introducing oxygen and using plasma free oxygen. Add additional process.

In order to achieve the above object and effect, the present invention provides a photovoltaic element comprising a first metal layer, a semiconductor layer, a barrier region and a transparent conductive layer, the semiconductor layer being disposed on the first metal layer, the barrier being The region is disposed on a sidewall of the semiconductor layer The conductive layer is disposed on the semiconductor layer, and the present invention transmits the barrier element to prevent the leakage current from being generated when the photoelectric element is applied to the photo sensor. The barrier region is formed in the process of patterning the semiconductor layer, and is formed by oxidation after the step of patterning the semiconductor layer.

An embodiment of the invention resides in that during the step of oxidizing, oxygen is introduced and the plasma is used to cause oxygen to form oxygen ions.

An embodiment of the invention resides in that in the step of oxidizing, the working pressure is adjusted to less than 50 Pa.

An embodiment of the invention resides in that in the step of oxidizing, the applied power is at least 1200 watts.

One embodiment of the invention resides in wherein the transparent conductive layer is patterned prior to the step of oxidizing.

An embodiment of the invention resides in wherein the semiconductor layer is patterned prior to the step of oxidizing.

One embodiment of the present invention resides in which the oxidation rate is adjusted to be from 900 to 1100 angstroms per minute in the step of patterning the semiconductor layer.

An embodiment of the invention resides in wherein the barrier zone is an oxide.

An embodiment of the invention resides in that the transparent conductive layer is disposed over the semiconductor layer and the barrier region.

10‧‧‧Optoelectronic components

11‧‧‧First metal layer

13‧‧‧Semiconductor layer

131‧‧‧Barrier zone

15‧‧‧Transparent conductive layer

20‧‧‧film transistor

21‧‧‧Second metal layer

23‧‧‧Insulation

25‧‧‧Channel layer

30‧‧‧Light sensor

31‧‧‧Substrate

33‧‧‧First passive layer

35‧‧‧second passive layer

37a-b‧‧‧Common electrode

371a-b‧‧‧Common electrode opening

39‧‧‧Protective layer

L1‧‧‧Light direction

1 is a schematic structural view of a first embodiment of the present invention; and FIG. 2A to FIG. 2C are flowcharts showing steps of a first embodiment of the present invention; FIG. 3 is a schematic view showing the structure of a sensor according to a first embodiment of the present invention; FIG. 4 is a schematic view showing the application of the first embodiment of the present invention; and FIGS. 5A to 5D: It is a flow chart of the steps of the second embodiment of the present invention.

For a better understanding and understanding of the features and advantages of the present invention, the preferred embodiments and the detailed description are given as follows: The purpose of the present invention is to: When the photoelectric element in the medium-light sensor is exposed to external light, the current generated by the photoelectric element generates leakage current from the sidewall of the semiconductor layer, thereby affecting the electrical properties of the photo sensor, so the present invention The semiconductor layer of the photovoltaic element reacts to form a barrier region to block current flow from the sidewall.

Please refer to the first drawing, which is a schematic structural view of a first embodiment of the present invention; the figure is for explaining the spatial relationship between the respective components of the photovoltaic element and their individual, as shown in the figure, the first embodiment of the present invention reveals A photovoltaic element 10 for a photosensor includes a first metal layer 11, a semiconductor layer 13, a barrier region 131, and a transparent conductive layer 15.

The semiconductor layer 13 is disposed on the first metal layer 11 , and the sidewall of the semiconductor layer 13 is provided with the barrier region 131 . The transparent conductive layer 15 is disposed on the semiconductor layer 13 .

Please refer to FIG. 2A to FIG. 2C, which are flowcharts of the steps of the first embodiment of the present invention; the figure is a method for fabricating the structure of the photovoltaic element according to the first embodiment of the present invention. First, the second A is to provide the first metal layer 11 and the semiconductor layer 13 is disposed on the first metal layer 11; then, as shown in the second B, the transparent conductive layer 15 is provided. It is disposed on the semiconductor layer 13; then, as shown in FIG. C, the sidewall of the semiconductor layer 13 is oxidized to react to form the barrier region 131 and disposed on the sidewall of the semiconductor layer 13.

In the above steps, the oxidation step can introduce oxygen and plasma into the process environment, and dissociate the oxygen into plasma ions to oxidize with the sidewalls of the semiconductor layer 13 to form the barrier region 131. In addition, during the oxidation process, the reaction time can be adjusted to a working pressure of less than 50 Pa, an applied power of at least 1200 watts, and a ruthenium oxidation rate of between 900 and 1100 angstroms per minute, which is a preferred manufacturing environment for the present invention.

Please refer to the third figure, which is a schematic structural view of a photosensor according to a first embodiment of the present invention. The figure shows the photosensor 10 when it is applied to a photo sensor 30. Structure, as shown, the photo sensor 30 includes a substrate 31, a thin film transistor 20, a first metal layer 11, an insulating layer 23, a photovoltaic element 10, and a first passive layer 33. a second passivation layer 35, a plurality of common electrodes 37a-b, a plurality of common electrode openings 371a-b, and a protective layer 39; wherein the thin film transistor 20 is disposed on the substrate 31 and is first Covered by the passive layer 33, the first passive layer 33 has an opening to expose a portion of the first metal layer 11 as the common electrode opening 371b; the photovoltaic element 10 is also disposed above the substrate 31, An insulating layer 23 is disposed between the substrates 31, and the photovoltaic element 10 is in contact with one side of the first passive layer 33; the second passive layer 35 covers the thin film transistor 20 and the photovoltaic element 10 above, and a portion of the photovoltaic element 10 is exposed through an opening as the common electrode opening 371a And the common electrode 37a-b is disposed on the common electrode opening 371a and the common electrode opening 371b.

Referring to the third figure, the thin film transistor 20 includes a second metal layer 21, an insulating layer 23, a channel layer 25, and a first metal layer 11 stacked upward in a set order. Undertake As described above, the first metal layer 11 located at the uppermost portion serves as the source and the drain of the thin film transistor 20, and the second metal layer 21 located at the lowermost portion serves as the gate of the thin film transistor 20, and The first metal layer 11 has an opening corresponding to the second metal layer 21 in the vertical direction, and the channel layer 25 is exposed such that the channel layer 25 is connected to the first passive layer 33.

However, the structure of the photosensor 30 and the thin film transistor 20 is only a preferred embodiment of the present invention for explaining the application mode of the photovoltaic element 10. In fact, the optoelectronic component 10 of the present invention can also be applied to other similarities. Structured light sensor 30. For example, the thin film transistor 20 is modified into a double gate thin film transistor, or a photo sensor 30 in which the common electrode openings 371a-b are not provided.

Please refer to the fourth figure, which is a schematic diagram of the application of the first embodiment of the present invention; the figure illustrates the function and effect of the photovoltaic element 10 of the first embodiment of the present invention when applied to the photo sensor 30, such as As shown, a light source is incident on the optoelectronic component 10 via a light travel direction L1 via a gap that is not obscured by the common electrode 37a-b, and a photocurrent will be along one side of the first metal layer 11. The drain connected to the thin film transistor 20 flows to the source of the other side of the first metal layer 11 via the channel region 25, and since the sidewall of the semiconductor layer 13 has the barrier region 131, the photoelectric effect can be prevented. A part of the generated current will leak from the sidewall of the semiconductor layer 13, thereby improving the electrical properties of the overall photosensor.

Please refer to the fifth through fifth figures, which are flowcharts of the steps of the second embodiment of the present invention; the figure is to provide another method for fabricating the photovoltaic element 10 for the sensor 30. First, the fifth A is to provide the first metal layer 11 and the semiconductor layer 13 is disposed on the first metal layer 11; then, as shown in FIG. 5B, the transparent conductive layer 15 is disposed on the semiconductor layer. 13; then, as shown in FIG. C, patterning the transparent conductive Layer 15; then, as shown in FIG. 5D, the semiconductor layer 13 is patterned to expose the sidewall of the semiconductor layer 13, and then the barrier region 131 is formed by oxidation.

In the above steps, in the oxidation of the sidewall of the semiconductor layer 13, the barrier region 131 may be formed by passing oxygen and plasma to form oxygen ions to oxidize the sidewalls of the semiconductor layer 13. In the second embodiment of the present invention, the parameters used in the oxidation process are the same as those in the first embodiment, and therefore will not be described again.

Moreover, the step of patterning the transparent conductive layer 15 and the step of patterning the semiconductor layer 13 in the second embodiment, and further performing the step of oxidizing the semiconductor layer 13 after the step of patterning the semiconductor layer 13 It can be completed under the same process environment parameters. It can be seen that the above steps belong to the same process. Therefore, in order to prevent leakage current from occurring in the sidewall of the semiconductor layer 13 in the photovoltaic element 10, the oxidation reaction is performed to form the barrier region 131, and Increase the cost of production by adding additional processes.

In summary, the present invention is a photovoltaic element for a photosensor comprising a first metal layer, a semiconductor layer, a transparent conductive layer and a barrier region, the barrier region being formed by oxidation reaction The sidewall of the semiconductor layer, whereby the photovoltaic element having the barrier region is applied to the photosensor, will make the sidewall of the semiconductor layer less likely to generate leakage current to improve the influence of leakage current on the photo sensor. In addition, the present invention further provides a step of oxidizing the semiconductor layer, after the step of patterning the transparent conductive layer and the step of patterning the semiconductor layer, introducing oxygen and dissolving it into oxygen ions by using a plasma, so that The transparent conductive layer and the sidewall of the semiconductor layer exposed after the semiconductor layer are patterned to generate an oxidation reaction, so that a structure for improving the electrical properties of the photosensor can be formed without adding an additional process.

Therefore, the present invention is indeed an invention that is novel, progressive, and available for industrial use. It should be in accordance with the requirements of the patent application of China's patent law. Undoubtedly, it is necessary to file a patent application in accordance with the law, and the Prayer Council will grant the patent as soon as possible.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, so that the shapes, structures, features, and spirits described in the claims of the present invention are equally changed. Modifications are intended to be included in the scope of the patent application of the present invention.

10‧‧‧Optoelectronic components

11‧‧‧First metal layer

13‧‧‧Semiconductor layer

131‧‧‧Barrier zone

15‧‧‧Transparent conductive layer

Claims (10)

A method for fabricating a photovoltaic element for a photosensor, comprising: providing a first metal layer; disposing a semiconductor layer over the first metal layer; and disposing a transparent conductive layer over the semiconductor layer; The sidewall of the semiconductor layer is oxidized to form a barrier region. A method of fabricating a photovoltaic element for a photosensor according to claim 1, wherein in the step of oxidizing, oxygen is introduced and plasma is used to cause oxygen to form oxygen ions. A method of fabricating a photovoltaic element for a photosensor according to claim 1, wherein in the step of oxidizing, the working pressure is adjusted to be less than 50 Pa. A method of fabricating a photovoltaic element for a photosensor according to claim 1, wherein in the step of oxidizing, a power of at least 1200 watts is applied. A method of fabricating a photovoltaic element for a photosensor according to claim 1, wherein the transparent conductive layer is patterned before the step of oxidizing. A method of fabricating a photovoltaic element for a photosensor according to claim 1, wherein the semiconductor layer is patterned before the step of oxidizing. A method of fabricating a photovoltaic element for a photosensor according to claim 6, wherein in the step of patterning the semiconductor layer, the oxidation rate is adjusted to be 900-1100 angstroms per minute. A photovoltaic element for a photosensor, comprising: a first metal layer; a semiconductor layer disposed on the first metal layer, and a sidewall of the semiconductor layer having a barrier region; A transparent conductive layer is disposed on the semiconductor layer; wherein the first metal layer is the same metal layer as one of the photosensors. A photovoltaic element for a photosensor according to claim 8, wherein the barrier region is an oxide. The photovoltaic element for a photosensor according to claim 8, wherein the transparent conductive layer is disposed on the semiconductor layer and the barrier region.