Nanoporous silicon processing equipment and optoelectronic components made therefrom

Abstract

This invention discloses a nanoporous silicon processing apparatus and the optoelectronic device fabricated therefrom. The apparatus includes a reaction tank, an electrochemical reaction device, a laser irradiation device, an ultrasonic vibration device, and a heating device. The reaction tank contains N-type and P-type silicon substrates, and by sequentially introducing and discharging processing fluids, a switchable fluid environment is created within the tank. This allows the silicon substrates to complete a continuous process from electrochemical etching to bonding without leaving the tank, reducing the risk of contamination and process errors. The electrochemical reaction device provides the electric field required for etching, while the laser irradiation device, combined with ultrasonic vibration, improves structural uniformity. The heating device controls the temperature of the reaction tank at approximately 90°C during the bonding stage to maintain reaction stability. The disclosed optoelectronic device includes a substrate, a metal thin film, and a nanoporous silicon substrate. The nanoporous silicon substrate is fabricated using the aforementioned apparatus and has an N-type and P-type nanoporous silicon stacked structure to enhance photoelectric conversion characteristics.

Claims

1. A nanoporous silicon processing apparatus, comprising: a reaction tank for accommodating an N-type silicon substrate and a P-type silicon substrate, wherein the reaction tank is configured to switch between multiple processing fluids by introducing and discharging them according to the electrochemical etching process, displacement process, and bonding process stages, thereby enabling the N-type silicon substrate and the P-type silicon substrate to complete a continuous process from electrochemical etching to bonding without leaving the reaction tank; an electrochemical action device comprising a pair of electrodes and a power supply, the pair of electrodes being disposed within the reaction tank and electrically connected to the power supply for performing electrochemical etching on the N-type silicon substrate and the P-type silicon substrate; and a laser irradiation device disposed on one side of the reaction tank for providing laser light to irradiate the N-type silicon substrate and / or the P-type silicon substrate during electrochemical etching. An ultrasonic vibration device is disposed in the reaction tank for applying ultrasonic vibration during electrochemical etching of the N-type silicon substrate and the P-type silicon substrate; and a heating device is disposed in the reaction tank for heating the reaction tank during bonding of the etched N-type silicon substrate and the P-type silicon substrate, so that the bonding temperature in the reaction tank is maintained at about 90˚C.

2. The nanoporous silicon processing equipment as described in claim 1, wherein, The N-type silicon substrate and the P-type silicon substrate are respectively placed in the reaction tank through a support.

3. The nanoporous silicon processing equipment as described in claim 2, wherein, The reaction tank wall has at least one processing window, through which the laser irradiation device irradiates laser light into the reaction tank.

4. The nanoporous silicon processing equipment as described in claim 3, wherein, The reaction tank is further equipped with a movable baffle to prevent the un-irradiated N-type silicon substrate or P-type silicon substrate from being affected by laser light when selectively irradiating the N-type silicon substrate or the P-type silicon substrate.

5. The nanoporous silicon processing apparatus as described in any one of claims 1 to 4, wherein, The processing fluids are etching solution, cleaning solution, interface displacement solution, and bonding reaction solution. In the electrochemical etching process, the reaction tank is filled with etching solution. In the displacement process, the reaction tank discharges etching solution and repeatedly introduces and discharges cleaning solution, then repeatedly introduces and discharges interface displacement solution, and retains the last interface displacement solution in the reaction tank. In the bonding process, bonding reaction solution is introduced into the reaction tank while interface displacement solution is present.

6. The nanoporous silicon processing equipment as described in claim 5, wherein, The etching solution is hydrofluoric acid, the cleaning solution is deionized water, the interface replacement solution is anhydrous ethanol, and the bonding reaction solution is anhydrous ethanol solution containing 3-aminopropyltriethoxysilane.

7. An optoelectronic element comprising: a substrate; a metal thin film disposed on the top side of the substrate; and a nanoporous silicon substrate, which is fabricated by a nanoporous silicon processing apparatus as described in any one of claims 1 to 6, stacked on the top side of the metal thin film, and the nanoporous silicon substrate having an N-type nanoporous silicon layer and a P-type nanoporous silicon layer sequentially stacked from top to bottom.

8. The optoelectronic element as described in claim 7, wherein, The substrate is made of glass.

9. The optoelectronic element as described in claim 7, wherein, The thickness of the metal film is less than 20 nm.

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