Method for preparing electroluminescent material on silicon wafer by using short pulse laser

Abstract

The invention discloses a method for preparing an electroluminescent material on a silicon wafer by using short pulse laser. Femtosecond laser acts on a semiconductor P-type silicon wafer in high vacuum, and a laser beam etches a circular hole array with the interval of 500 micrometers on the silicon wafer through a convergent light path; then, laser beam spots are expanded to uniformly distributed round spots with the diameter of 1 cm through a beam expanding and collimating light path, the round spots act on a silicon wafer for laser annealing treatment, the annealing atmosphere is an oxygen blowing environment, and nano-sized silicon quantum dots grow; depositing pulse laser on a silicon wafer in a nitrogen atmosphere to form an N-type silicon film with the thickness of 100 nanometers; and finally, plating an aluminum electrode on the back surface of the P-type silicon, and plating an ITO transparent electrode on the N-type silicon, thereby completing the preparation of the electroluminescent material and device. A voltage-stabilized direct-current power supply is connected with an upper electrode, and pulsating direct-current voltage of 5-10 volts (rectangular pulse once per second) is applied, so that strong red light on the silicon wafer can be seen by naked eyes, and a light-emitting broad peak with the wavelength of 600-800 nanometers can be measured by a fiber optic spectrometer.

Description

Technical Field

[0001] The invention relates to the field of semiconductor science and technology, in particular to a method for preparing electroluminescent material on a silicon wafer by using a short pulse laser. Background Art

[0002] Over the past 20 years, we have been experiencing a transition from the electronic information age to the photonic information age. The invention of fiber erbium-doped amplifiers and Raman amplifiers has promoted the realization of all-optical network communications. Currently, we are experiencing a critical development stage of on-chip and off-chip interconnection integration of silicon-based photonics. The development and application of laser luminescent materials and devices on silicon wafers is particularly important. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing electroluminescent materials on silicon wafers using femtosecond lasers, which constructs a research and development and application research platform for luminescent materials and devices on silicon wafers. Its scientific and technological process adopts a purely physical process and is green and environmentally friendly, which can promote the industrial development of silicon-based optoelectronic materials and devices.

[0004] The present invention is implemented as follows: a method for preparing electroluminescent materials on silicon wafers using short pulse lasers, using near-infrared pulse lasers to act on semiconductor P-type silicon wafers in high vacuum, and etching a circular hole array on the silicon wafer through a converging optical path with a laser beam, wherein the hole diameter and hole depth are 30 to 50 microns; then, the laser beam spot is expanded to a uniformly distributed circular spot with a diameter of 1 cm through a beam expansion and collimation optical path, and acts on the silicon wafer, and laser annealing is performed in an oxygen gas atmosphere to grow nano-sized silicon quantum dots; a 100-nanometer-thick N-type silicon film is deposited on the silicon wafer in a nitrogen atmosphere using a pulse laser; finally, an aluminum electrode is plated on the back of the P-type silicon, and an ITO transparent electrode is plated on the N-type silicon, thereby completing the preparation of the electroluminescent material and device.

[0005] The pulse laser is a femtosecond pulse laser, a picosecond pulse laser or a nanosecond pulse laser, with a pulse width of less than 100 nanoseconds, an average power of 5 to 20 W, and a repetition rate of 3 to 30 K / s.

[0006] The photon power density of the pulse acting on the semiconductor P-type silicon wafer is about 10KW / cm 2 .

[0007] The high vacuum is 10 -6 Pa; the laser annealing treatment uses an oxygen atmosphere pressure of 10-100Pa, and the nitrogen atmosphere pressure of the pulsed laser deposited on the silicon wafer in a nitrogen atmosphere to form a 100-nanometer thick N-type silicon film is 10-100Pa.

[0008] When a laser beam is used to etch a circular hole array on a silicon wafer through a converging optical path, the laser beam spot diameter is controlled to be 10 to 50 microns, and a circular hole array with a spacing of 500 microns is etched on the silicon wafer, and the hole diameter and hole depth are 30 to 50 microns.

[0009] In the laser annealing treatment, the temperature of the silicon wafer is controlled to be 900° C., the annealing time is 20 to 30 minutes, and the annealing atmosphere is an oxygen blowing environment.

[0010] The method uses pulse laser deposition to form a 100-nanometer-thick N-type silicon film on a silicon wafer in a nitrogen atmosphere, and uses pulse laser deposition in a nitrogen 10-100 Pa chamber atmosphere to prepare the upper N-type silicon film.

[0011] The aluminum electrode is plated on the back of the P-type silicon by pulse laser deposition to plate the positive electrode aluminum electrode, and the negative electrode ITO transparent electrode is plated on the N-type silicon by pulse laser deposition to complete the preparation of electroluminescent materials and devices.

[0012] The above method is used to build a research and development and application research platform for luminescent materials and devices on silicon wafers. The scientific and technological process using pure physics is green and environmentally friendly, which can promote the industrial development of silicon-based optoelectronic materials and devices. The obtained product is connected to the electrode with a regulated DC power supply, and a pulsating DC voltage of 5 to 10 volts (rectangular pulse once per second) is added. The strong red light on the silicon wafer can be seen with the naked eye, and the luminescent broad peak with a wavelength of 600 to 800 nanometers is measured with a fiber optic spectrometer. This achievement can be directly used for silicon chip integrated light sources and light source pools for various optical module operations, which can solve the light source problem of silicon-based integrated quantum computing; it can also move the luminescent band to the optical communication window. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the principle structure of using femtosecond laser to prepare electroluminescent materials on silicon wafers

[0014] Figure 2 Schematic diagram of laser annealing to grow quantum dots

[0015] Figure 3 Nano-sized quantum dots can be observed in transmission electron microscope (TEM) images.

[0016] Figure 4 The structure of the electroluminescent device prepared on a silicon wafer using a femtosecond laser (below) and the electroluminescent imaging seen by the naked eye (above)

[0017] Figure 5 Imaging spectrum of electroluminescent device fabricated on silicon wafer using femtosecond laser DETAILED DESCRIPTION

[0018] Example 1 of the present invention: Preparation of quantum dot electroluminescent materials and devices on silicon wafers using near-infrared short-pulse lasers, with a pulse width of about 100 femtoseconds, an average power of 5 to 20W, and a repetition rate of 3 to 30K / s. -6 Pa) acts on a semiconductor P-type silicon wafer, controls the diameter of the laser beam spot to 10 to 50 microns through a converging optical path, etches a circular hole array (200x200) with a spacing of 500 microns on the silicon wafer, and the hole diameter and hole depth are 30 to 50 microns; then, expands the laser beam spot to a uniformly distributed circular spot with a diameter of 1 cm through a beam expansion and collimation optical path in an oxygen atmosphere, acts on the silicon wafer for laser annealing, controls the temperature of the silicon wafer at 900°C with a remote-controlled thermometer, and the annealing time is 20 to 30 minutes in an oxygen-blown atmosphere to grow nano-sized silicon quantum dots; uses pulsed laser deposition to make a 100-nanometer-thick N-type silicon film on the silicon wafer in a nitrogen atmosphere; finally, plates an aluminum electrode on the back of the P-type silicon, and plates an ITO transparent electrode on the N-type silicon, completing the preparation of electroluminescent materials and devices. Connect the electrodes with a regulated DC power supply and add a pulsating DC voltage of 5 to 10 volts (rectangular pulse once per second). You can see a strong red light on the silicon wafer with the naked eye, and measure a broad peak of luminescence with a wavelength of 600 to 800 nanometers with a fiber optic spectrometer. Figure 5 shown.

[0019] Example 2 of the present invention: Preparation of quantum dot electroluminescent materials and devices on silicon wafers using near-infrared short-pulse lasers, with a 1064-nanometer wavelength nanosecond laser pulse width of about 60 nanoseconds, an average power of 5 to 20 W, and a repetition rate of 3 to 30 K / s. The nanosecond laser is used in a high vacuum (10 -6 Pa) acts on a semiconductor P-type silicon wafer, controls the laser beam spot diameter to 10 to 50 microns through a converging optical path, etches a circular hole array (200x200) with a spacing of 500 microns on the silicon wafer, and the hole diameter and hole depth are 30 to 50 microns; then, expands the laser beam spot to a uniformly distributed circular spot with a diameter of 1 cm through a beam expansion and collimation optical path in an oxygen atmosphere, acts on the silicon wafer for laser annealing, controls the silicon wafer temperature at 1000°C with a remote-controlled thermometer, and the annealing time is 20 to 30 minutes in an oxygen-blown annealing atmosphere to grow nano-sized silicon quantum dots; uses pulsed laser deposition to make a 100-nanometer-thick N-type silicon film on the silicon wafer in a nitrogen atmosphere; finally, plates an aluminum electrode on the back of the P-type silicon, and plates an ITO transparent electrode on the N-type silicon, completing the preparation of electroluminescent materials and devices. Connect the electrodes with a regulated DC power supply and add a pulsating DC voltage of 5 to 10 volts (rectangular pulse once per second), and you can see a strong red light on the silicon wafer with the naked eye. Figure 4 shown.

Claims

1. A method for preparing electroluminescent material on a silicon wafer using a short pulse laser, characterized in that: A near-infrared pulsed laser is used in a high vacuum to act on a semiconductor P-type silicon wafer, and the laser beam is used to etch a circular hole array on the silicon wafer through a converging optical path. The hole diameter and hole depth are 30 to 50 microns. Then, the laser beam spot is expanded to a uniformly distributed circular spot with a diameter of 1 cm through a beam expansion and collimation optical path, and then acted on the silicon wafer and laser annealed in an oxygen gas atmosphere to grow nano-sized silicon quantum dots. A pulsed laser is used to deposit a 100-nanometer-thick N-type silicon film on the silicon wafer in a nitrogen atmosphere. Finally, an aluminum electrode is plated on the back of the P-type silicon, and an ITO transparent electrode is plated on the N-type silicon to complete the preparation of electroluminescent materials and devices.

2. The method for preparing electroluminescent material on silicon wafer using short pulse laser according to claim 1, characterized in that: The pulse laser is a femtosecond pulse laser, a picosecond pulse laser or a nanosecond pulse laser, with a pulse width of less than 100 nanoseconds, an average power of 5 to 20 W, and a repetition rate of 3 to 30 K / s.

3. The method for preparing electroluminescent material on silicon wafer using short pulse laser according to claim 1, characterized in that: The photon power density of the pulse acting on the semiconductor P-type silicon wafer is about 10KW / cm 2 .

4. The method for preparing electroluminescent material on silicon wafer using short pulse laser according to claim 1, characterized in that: The high vacuum is 10 -6 Pa; the laser annealing treatment uses an oxygen atmosphere pressure of 10-100Pa, and the nitrogen atmosphere pressure of the pulsed laser deposited on the silicon wafer in a nitrogen atmosphere to form a 100-nanometer thick N-type silicon film is 10-100Pa.

5. The method for preparing electroluminescent material on silicon wafer using short pulse laser according to claim 1, characterized in that: When a laser beam is used to etch a circular hole array on a silicon wafer through a converging optical path, the laser beam spot diameter is controlled to be 10 to 50 microns, and a circular hole array with a spacing of 500 microns is etched on the silicon wafer, and the hole diameter and hole depth are 30 to 50 microns.

6. The method for preparing electroluminescent material on silicon wafer using short pulse laser according to claim 1, characterized in that: In the laser annealing treatment, the temperature of the silicon wafer is controlled to be 900° C., the annealing time is 20 to 30 minutes, and the annealing atmosphere is an oxygen blowing environment.

7. The method for preparing electroluminescent material on silicon wafer using short pulse laser according to claim 1, characterized in that: The method uses pulse laser deposition to form a 100-nanometer-thick N-type silicon film on a silicon wafer in a nitrogen atmosphere, and uses pulse laser deposition in a nitrogen 10-100 Pa chamber atmosphere to prepare the upper N-type silicon film.

8. The method for preparing electroluminescent material on silicon wafer using short pulse laser according to claim 1, characterized in that: The aluminum electrode is plated on the back of the P-type silicon by pulse laser deposition to plate the positive electrode aluminum electrode, and the negative electrode ITO transparent electrode is plated on the N-type silicon by pulse laser deposition to complete the preparation of electroluminescent materials and devices.

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