CN113724756B - Nonvolatile decimal photoelectric memory based on waveguide grating structure - Google Patents

Abstract

A non-volatile decimal photoelectric memory based on a waveguide grating structure belongs to the technical field of information. The memory comprises a layer bottom, an optical waveguide, a conductive electrode material and a phase change material film. The phase change material film is deposited on the waveguide in an array grating structure, the state of the phase change material film can be changed through an electric signal, and the number of crystalline states and amorphous states can be programmed and controlled, so that data can be written into/erased from the grating array. The phase change material film has great difference in optical constants between crystalline and amorphous states, and can change the light propagation behavior in the optical waveguide. Thus, the written data can be read out by utilizing the difference in transmittance of the optical signal. The nonvolatile ultrafast phase change material of the invention combines the universality of electric drive and the ultrafast property of optical reading, realizes low loss and large capacity of the memory, has simple design structure and convenient integration, and lays a foundation for the development of future photoelectric devices.

Description

A non-volatile decimal optical memory based on waveguide grating structure

Technical field

The invention relates to an optoelectronic hybrid device, which belongs to the field of information technology, and specifically relates to a non-volatile decimal optoelectronic memory based on a waveguide grating structure.

Background technique

In recent decades, due to the rapid development of Internet technology, semiconductor memories for recording information and storing data have played an irreplaceable and important role. Currently, memories on the market are mainly divided into two types: volatile memory and non-volatile memory. The contents of dynamic random access memory (DRAM) memory cells can be written and read at will, and the writing speed is independent of position, but this kind of memory is volatile and data will be lost when power is turned off. Flash memory (FLASH) is a non-volatile memory that can still preserve the integrity of data even when the power is off; however, this structure erases data in units of fixed areas rather than in units of single bytes. remove.

Phase change memory (PCRAM) is considered to be the most potential non-volatile memory. Its key materials include silicon substrate, phase change material recording film, heating electrode material, insulating material and extraction electrode material. The principle is to use a phase-change material film to transition between crystalline and amorphous states for writing, reading and erasing operations. At present, the difference in resistance or optical constants between crystalline and amorphous states is mainly used. When the phase change material film is in the amorphous state, it exhibits a high resistance value; using the thermal effect of the electrical signal, the amorphous state of the phase change material can be converted into a crystalline state; when the phase change material film is in the amorphous state, it exhibits a low resistance value. resistance. Binary data storage can be achieved using this resistance difference. The erasing electrical signal can be used to change the phase change material film from the crystalline state to the amorphous state, thereby achieving the erasing operation. The phase-change optical disc uses the optical difference between the crystalline and amorphous states of the phase-change material film to achieve writing, reading and erasing operations.

However, current phase change memory is mainly based on binary data for writing and reading, and can only store one data point in a unit area, which greatly reduces the data capacity. And with the development of photonic chips, it is also imperative to realize optical waveguide memory. Thin films of phase change materials can regulate the transmitted light in waveguides and exhibit different properties in the crystalline and amorphous states. Combining the above characteristics, a non-volatile decimal optoelectronic memory based on phase-change material array waveguide grating is proposed. Using electrical signals for writing and erasing and using optical signals for reading is beneficial to signal transmission and promotes the development of future electro-optical network information technology.

Contents of the invention

In view of the defects and improvement needs of existing memories, the present invention proposes a non-volatile decimal photoelectric memory based on phase-change material array waveguide gratings, with the purpose of increasing storage capacity and reducing losses. In order to solve the above technical problems, the present invention mainly provides the following technical solutions.

The present invention first provides a phase change material for optoelectronic memory. The phase change material films described above include, but are not limited to, chalcogenide phase change materials such as Ge ₂ Sb ₂ Te ₅ , GeTe, and Sb ₂ Te ₃ .

The phase change material film is prepared by magnetron sputtering.

A non-volatile decimal photoelectric memory based on phase change material array waveguide grating, which is characterized in that the phase change material thin film array grating is used to store decimal data;

The specific structure includes the following: the optical waveguide is located on the substrate, the phase change material thin film grating array is deposited on the upper surface of the waveguide, and the light in the optical waveguide is used to read data; in each phase change material thin film grating structure, there are two Electrode materials are introduced on the side to energize and heat the phase change material film, changing the phase state of the phase change material film, thereby realizing data writing and erasing.

The phase change material thin film grating arrays are arranged side by side along the length direction of the optical waveguide, preferably with nine grating structures.

When they are all crystalline, it means writing "0"; there are several amorphous states, which means how many are written, and the amorphous state starts from one end of the array and is continuous; when 1 amorphous state , when there are 8 crystal states, it means writing "1". When there are 2 amorphous states and 7 crystalline states, it means writing "2". By analogy, when it is all amorphous, it means writing "9".

Preferably, the width of each phase change material film grating structure is equal to the width of the optical waveguide, preferably 500 nm. The length of each phase change material film grating structure, that is, the length along the length of the optical waveguide, is preferably 250 nm; the grating period is 1000 nm. .

Preferably, the thickness of the phase change material film is selected from left to right as two 10nm thicknesses, four 20nm thicknesses, and three 30nm thicknesses.

Preferably, the thickness of the optical waveguide is selected to be 220nm, and the width is selected to be 500nm.

Preferably, the conductive electrode material is gold, aluminum, copper, tungsten, etc.

Compared with the existing technology, the beneficial effects of the present invention

The invention proposes a non-volatile decimal photoelectric memory based on phase change material array waveguide grating. The phase change material thin film array grating can transform between crystalline and amorphous states under the action of electrodes. Through programming processing, the number of crystalline and amorphous states of the phase change material thin film array grating can be controlled, so that data can be written and erased. The phase change material film can control the light field, and the stored data can be read out using the transmission of light. Thus realizing the process of electrical storage and optical reading. Decimal storage can increase the storage capacity of data. After optical reading, the signal does not need to be converted into light for transmission, which reduces energy consumption. It has important application value for future large-scale integrated photoelectric networks.

Description of the drawings

Figure 1 is a schematic structural diagram of a non-volatile decimal optical memory based on a waveguide grating structure.

Figure 2 is a schematic diagram of the designed decimal photoelectric memory for reading "0".

Figure 3 is a schematic diagram of the designed decimal photoelectric memory reading "1".

Figure 4 is a schematic diagram of the designed decimal photoelectric memory reading "2".

Figure 5 is a schematic diagram of the designed decimal photoelectric memory reading "3".

Figure 6 is a schematic diagram of the designed decimal photoelectric memory for reading "4".

Figure 7 is a schematic diagram of the designed decimal photoelectric memory for reading "5".

Figure 8 is a schematic diagram of the designed decimal photoelectric memory for reading "6".

Figure 9 is a schematic diagram of the designed decimal photoelectric memory for reading "7".

Figure 10 is a schematic diagram of the designed decimal photoelectric memory for reading "8".

Figure 11 is a schematic diagram of the designed decimal photoelectric memory for reading "9".

Figure 12 is a schematic diagram of the decimal order of the designed decimal photoelectric memory.

Among them: 1 is the substrate, 2 is the optical waveguide, 3 is the electrode material, and 4 is the phase change material film covering layer.

Detailed ways

In order to explain the purpose, principle and technical solution of the present invention more clearly, the present invention will be further described below in conjunction with the accompanying drawings and examples. It should be understood that this example is only suitable for further describing the present invention in detail and is not used to limit the present invention and cannot be understood as limiting the scope of protection of the present invention.

It should be noted that the diagrams provided in this example only illustrate the basic configuration of the present invention. The number, shape and size of components can be changed at will, and the component layout may also be more complex.

The invention uses electrical signals to write or erase information in the phase change material film, and utilizes the different control characteristics of the phase change material film in the crystalline and amorphous states of light in the waveguide to realize the reading of information.

As shown in Figure 1, a schematic structural diagram of a non-volatile decimal optoelectronic memory based on phase change material array waveguide grating, including substrate 1, optical waveguide 2, electrode material 3, and phase change material film covering layer 4. Among them, the thickness of the optical waveguide is selected as 220nm, and the width is selected as 500nm. The phase change material film is 500nm wide and 250nm long. The grating period is 1000nm. The thickness of the phase change material film is selected as different thicknesses of 10nm, 20nm and 30nm. The conductive electrode material may be gold, aluminum, copper, tungsten, etc.

Example 1

(1) Use electron beam exposure and reactive ion etching to prepare the optical waveguide structure; deposit phase change material thin film array gratings through magnetron sputtering and sputtering windows, and deposit conductive materials.

(2) Through programming, 9 phase change material film light fields are energized respectively. When the number of crystalline and amorphous states of the optical phase change material film is different, it means that the written data is different. When it is all crystalline, it means writing "0". When there is 1 amorphous state and 8 crystalline states, it means writing "1". When there are 2 amorphous states and 7 crystalline states, it means writing "2". By analogy, when it is all amorphous, it means writing "9".

(3) Since the phase change material film has different control characteristics of the light field in the crystalline and amorphous states, it can facilitate the transmission of light and data reading. As shown in Figure 2, where 1 represents the amorphous state and 0 represents the crystalline state. When writing, it is all crystalline. When reading, the light transmittance is 0.095182, which is expressed as "0". As shown in Figure 3, when writing 1 amorphous state and 8 crystalline states, the transmittance of reading light is 0.15545, expressed as "1". By analogy, Figures 4 to 11 respectively show the reading results of other data.

(4) Based on the above, decimal writing and reading are implemented. As shown in Figure 12, the read data are 0.095182, represented as "0", 0.15545, represented as "1", 0.25729 represented as "2", and 0.38368 represented is "3", 0.47276 is represented as "4", 0.57160 is represented as "5", 0.65589 is represented as "6", 0.74844 is represented as "7", 0.80859 is represented as "8", and 0.97451 is represented as "9".

The above-mentioned specific description further explains the purpose, technical solution and beneficial effects of the present invention. The above-mentioned are only specific implementation examples of the present invention and do not limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (5)

1. The non-volatile decimal photoelectric memory based on the phase-change material array waveguide grating is characterized in that decimal data are stored by utilizing the phase-change material thin film array grating;

the specific structure comprises the following steps: the optical waveguide is positioned on the substrate, the phase change material film grating array is deposited on the upper surface of the waveguide, and data is read by utilizing light in the optical waveguide; electrode materials are introduced into two side surfaces of each phase change material film grating structure, and the phase change material films are electrified and heated to change the phase states of the phase change material films, so that data writing and erasing are realized;

the phase change material film grating arrays are arranged in parallel along the length direction of the optical waveguide and have 9 grating structures;

when all crystalline, it means that a "0" is written; written to are several amorphous representations, the amorphous states beginning at one end of the array and continuing; when 1 amorphous, 8 crystalline states, this indicates writing of "1"; when 2 amorphous states, 7 crystalline states, this indicates writing "2"; when 3 amorphous, 6 crystalline, represent write 3; when 4 amorphous, 5 crystalline, represent write 4; when 5 amorphous, 4 crystalline, represent write 5; when 6 amorphous, 3 crystalline, represent write 6; when 7 amorphous, 2 crystalline, represent write 7; when 8 amorphous, 1 crystalline, represent write 8; when all amorphous, it means writing "9";

(3) The phase change material film has different regulation and control characteristics on the light field when in a crystalline state and an amorphous state, so that the transmission of light is facilitated, and data is read; the crystalline state is all crystalline, and the transmittance of light during reading is 0.095182, which is denoted as "0"; when 1 amorphous state and 8 crystalline states are written, the transmittance of light at the time of reading is 0.15545, which is expressed as "1".

2. A phase change material arrayed waveguide grating-based nonvolatile decimal optoelectronic memory according to claim 1 wherein the width of each phase change material thin film grating structure is equal to the width of the optical waveguide and is 500nm, and the length of each phase change material thin film grating structure, namely the length along the length direction of the optical waveguide, is 250nm; the grating period is 1000nm.

3. A phase change material arrayed waveguide grating based non-volatile decimal optoelectronic memory in accordance with claim 1 wherein the thickness of the thin film of phase change material is selected to be 2 10nm, 4 20nm and 3 30nm in sequence from left to right.

4. A phase change material arrayed waveguide grating based non-volatile decimal optoelectronic memory in accordance with claim 1 wherein the optical waveguide is selected to have a thickness of 220nm and a width of 500nm.

5. A phase change material arrayed waveguide grating based non-volatile decimal optoelectronic memory in accordance with claim 1 wherein the electrode material is selected from the group consisting of gold, aluminum, copper and tungsten.