Method for preparing diamond-like film on germanium substrate

Abstract

The invention relates to a method for preparing diamond-like film by depositing plasma activated chemical vapor on a germanium substrate, comprising the following steps: (1) placing germanium substrate on a cavity negative plate; (2) vacuumizing cavity, introducing CH4 gas, regulating cavity air pressure, and balancing for 3-5 minutes; (3) building up luminance to the radio frequency power, and regulating power; (4) regulating working air pressure to be 30-45 Pa, CH4 gas flow to be 20-30sccm, and regulating the matching capacitance to lead the reflection power to reach the minimum value; (5) depositing for 14-18min, and closing the radio frequency power; (6) cooling for 10min, taking out the germanium (Ge) substrate, and clearing the cavity; (7) placing the germanium (Ge) substrate again, vacuumizing the cavity, building up luminance to the radio frequency power, closing the radio frequency power after bombarding the sample for 70-90s, closing the radio frequency power, and continuously pumping high vacuum; and (8) repeating secondary deposition. The method has rapid deposition rate, large deposition area and relatively simple and convenient process. The diamond-like film obtained by the method has good anti-reflection and protection effect on germanium (Ge) substrate.

Description

technical field

[0001] The invention relates to a method for preparing a diamond-like film on a germanium (Ge) substrate, in particular to a method for preparing a diamond-like film on a germanium (Ge) substrate by plasma chemical vapor deposition. Background technique

[0002] In 1971, Aisenberg and Chabot first used ion beam deposition technology to obtain a hard carbon film with physical properties close to or similar to diamond at room temperature. It is inferred from X-ray diffraction analysis that this hard carbon film may have a crystallite region with a lattice constant similar to that of diamond. They call this hard carbon film a diamond-like carbon film (Diamond-like Carbon, DLC. Hereinafter referred to as diamond-like carbon film) membrane).

[0003] Diamond-like film is a low-mobility semiconductor with fluorescence effect at room temperature and low electron affinity, good wear resistance, low friction coefficient, good thermal conductivity, infrared transparen...

Examples

Embodiment 1

[0039] Diamond-like carbon films were prepared on larger Ge substrates by plasma chemical vapor deposition.

[0040] (1) Take a relatively large n-type single crystal Ge substrate 3 with a specification of φ200mm×5mm, and clean the substrate first to eliminate residues, oil stains and residual stress caused by optical cold processing of the substrate. The specific process Yes: put substrate 3 into acetone for 15 minutes of ultrasonic cleaning, and then dry it with a hair dryer.

[0041] (2) Place the Ge substrate on the lower plate 2, and then vacuum the cavity to less than 1×10 through the vacuum pump 6. -3 Pa, followed by CH 4 Gas 7, adjust the air pressure of the chamber to 45Pa, and equilibrate for 5 minutes.

[0042] (3) The radio frequency power supply 1 starts and adjusts the power to make it stable between 900W.

[0043](4) Stabilize other process parameters in the following range: working pressure 45Pa, CH 4 The flow rate of the gas 7 is controlled at 30 sccm, an...

Embodiment 2

[0052] Diamond-like carbon films were prepared on smaller Ge substrates by plasma chemical vapor deposition.

[0053] (1) Take a smaller n-type single crystal Ge substrate 3 with a specification of φ20mm×2.2mm, and clean the substrate first. The specific process is: put the substrate 3 in acetone for 10 minutes for ultrasonic cleaning, Then blow dry with a hair dryer.

[0054] (2) Place the Ge substrate on the lower plate 2, and then vacuum the cavity to less than 1×10 through the vacuum pump 6. -3 Pa, followed by CH 4 Gas 7, the purity of the methane gas used is 99.99%, the air pressure of the chamber is adjusted to 30Pa, and the balance is 3 minutes.

[0055] (3) The radio frequency power supply 1 starts and adjusts the power to make it stable at 800W.

[0056] (4) Stabilize other process parameters in the following ranges: working pressure 30Pa, CH 4 The flow rate of the gas 7 is controlled at 20 sccm, and the matching capacitor is adjusted to minimize the reflected po...

Embodiment 3

[0064] Diamond-like carbon films were prepared on medium Ge substrates by plasma chemical vapor deposition.

[0065] (1) Take a medium-sized n-type single crystal Ge substrate 3 with a specification of φ80mm×3.2mm, and clean the substrate first. The specific process is: put the substrate 3 in acetone for 10 minutes for ultrasonic cleaning, Then blow dry with a hair dryer.

[0066] (2) Place the Ge substrate on the lower plate 2, and then vacuum the cavity to less than 1×10 through the vacuum pump 6. -3 Pa, followed by CH 4 Gas 7, the purity of the methane gas used is 99.99%, the air pressure of the chamber is adjusted to 40 Pa, and the balance is 3 minutes.

[0067] (3) The radio frequency power supply 1 starts and adjusts the power to make it stable at 850W.

[0068] (4) Stabilize other process parameters in the following ranges: working pressure 40Pa, CH 4 The flow rate of the gas 7 is controlled at 25 sccm, and the matching capacitor is adjusted to minimize the reflect...

technical field

[0001] The invention relates to a method for preparing a diamond-like film on a germanium (Ge) substrate, in particular to a method for preparing a diamond-like film on a germanium (Ge) substrate by plasma chemical vapor deposition. Background technique

[0002] In 1971, Aisenberg and Chabot first used ion beam deposition technology to obtain a hard carbon film with physical properties close to or similar to diamond at room temperature. It is inferred from X-ray diffraction analysis that this hard carbon film may have a crystallite region with a lattice constant similar to that of diamond. They call this hard carbon film a diamond-like carbon film (Diamond-like Carbon, DLC. Hereinafter referred to as diamond-like carbon film) membrane).

[0003] Diamond-like film is a low-mobility semiconductor with fluorescence effect at room temperature and low electron affinity, good wear resistance, low friction coefficient, good thermal conductivity, infrared transparen...

Examples

Embodiment 1

[0039] Diamond-like carbon films were prepared on larger Ge substrates by plasma chemical vapor deposition.

[0040] (1) Take a relatively large n-type single crystal Ge substrate 3 with a specification of φ200mm×5mm, and clean the substrate first to eliminate residues, oil stains and residual stress caused by optical cold processing of the substrate. The specific process Yes: put substrate 3 into acetone for 15 minutes of ultrasonic cleaning, and then dry it with a hair dryer.

[0041] (2) Place the Ge substrate on the lower plate 2, and then vacuum the cavity to less than 1×10 through the vacuum pump 6. -3 Pa, followed by CH 4 Gas 7, adjust the air pressure of the chamber to 45Pa, and equilibrate for 5 minutes.

[0042] (3) The radio frequency power supply 1 starts and adjusts the power to make it stable between 900W.

[0043](4) Stabilize other process parameters in the following range: working pressure 45Pa, CH 4 The flow rate of the gas 7 is controlled at 30 sccm, an...

Embodiment 2

[0052] Diamond-like carbon films were prepared on smaller Ge substrates by plasma chemical vapor deposition.

[0053] (1) Take a smaller n-type single crystal Ge substrate 3 with a specification of φ20mm×2.2mm, and clean the substrate first. The specific process is: put the substrate 3 in acetone for 10 minutes for ultrasonic cleaning, Then blow dry with a hair dryer.

[0054] (2) Place the Ge substrate on the lower plate 2, and then vacuum the cavity to less than 1×10 through the vacuum pump 6. -3 Pa, followed by CH 4 Gas 7, the purity of the methane gas used is 99.99%, the air pressure of the chamber is adjusted to 30Pa, and the balance is 3 minutes.

[0055] (3) The radio frequency power supply 1 starts and adjusts the power to make it stable at 800W.

[0056] (4) Stabilize other process parameters in the following ranges: working pressure 30Pa, CH 4 The flow rate of the gas 7 is controlled at 20 sccm, and the matching capacitor is adjusted to minimize the reflected po...

Embodiment 3

[0064] Diamond-like carbon films were prepared on medium Ge substrates by plasma chemical vapor deposition.

[0065] (1) Take a medium-sized n-type single crystal Ge substrate 3 with a specification of φ80mm×3.2mm, and clean the substrate first. The specific process is: put the substrate 3 in acetone for 10 minutes for ultrasonic cleaning, Then blow dry with a hair dryer.

[0066] (2) Place the Ge substrate on the lower plate 2, and then vacuum the cavity to less than 1×10 through the vacuum pump 6. -3 Pa, followed by CH 4 Gas 7, the purity of the methane gas used is 99.99%, the air pressure of the chamber is adjusted to 40 Pa, and the balance is 3 minutes.

[0067] (3) The radio frequency power supply 1 starts and adjusts the power to make it stable at 850W.

[0068] (4) Stabilize other process parameters in the following ranges: working pressure 40Pa, CH 4 The flow rate of the gas 7 is controlled at 25 sccm, and the matching capacitor is adjusted to minimize the reflect...

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