CN103160800A - Method for preparing fluorine-containing carbon-based film on silicon substrate surface - Google Patents

Abstract

The invention discloses a method for preparing fluorine-containing carbon-based film on a silicon substrate surface. According to the method for preparing the fluorine-containing carbon-based film on the silicon substrate surface, carbon tetrafluoride serves as a precursor gas, an enhancement type chemical vapor deposition method is used, and the film is deposited on the surface of a polished silicon wafer. The method for preparing the fluorine-containing carbon-based film on the silicon substrate surface is low in cost, short in cycle, simple in operation and convenient to operate. The prepared film is compact, stable, even and good in binding force with a substrate, and has good abrasion resistance and damage resistance.

Description

Method at the fluorine-containing carbon-base film of silicon base surface preparation

Technical field

The present invention relates to a kind of method at the fluorine-containing carbon-base film of silicon base surface preparation.

Background technology

Diamond-like carbon film has high rigidity, low-friction coefficient, good erosion resistance, is widely used in the aspects such as aerospace, steamer, road transporting tool, cutter, medicine equipment.But DLC film tribological property under humid atmosphere is relatively poor, and due to excessive self thickness that limits of self internal stress.Therefore, improve wear-resistant impairment ability by mixing F, reduce the surface energy of film, to reduce the moisture sensitivity of film friction coefficient, also can improve its internal stress simultaneously.

Aspect depositing operation, diamond-like carbon film is all at exemplar surface deposition film usually by technology such as sputter, electric arcs.But. more fine and close, stable, even, good with substrate caking power by the standby DLC film of pulse direct current PECVD (plasma reinforced chemical meteorology deposition) legal system, show excellent wear-resistant invulnerability, and this method cost is low, the cycle is short, and is easy and simple to handle.

Tetrafluoro-methane is the plasma etch gases of consumption maximum in present microelectronics industry, and its high-purity gas and tetrafluoro-methane high-purity gas are joined the mixture of high-purity argon gas, can be widely used in the etching of silicon, silicon-dioxide, silicon nitride, phosphorosilicate glass and W film material.Therefore, when adopting CF4-CH4-H2 reaction and plasma system, by regulating the ratio of three kinds of gases, can reach the trim point of etch rate and sedimentation rate, this makes the fluorine-containing carbon-base film that deposits can keep the premium properties of original diamond-like film, can successfully introduce again fluorine element and reduce former stress in thin films, improves wear-resistant impairment ability.

Summary of the invention

The object of the present invention is to provide a kind of method at the fluorine-containing carbon-base film of silicon base surface preparation.

We have invented and have a kind ofly processed with tetrafluoro-methane the method with excellent wear-resisting impairment performance carbon-base film of preparing, and the method has huge application potential in wear-resistant impairment field, and is expected to realize large-scale industrial production.

The present invention as precursor gas, prepares the method with excellent wear-resisting impairment performance fluorocarbon-containing film with tetrafluoro-methane by doping way.Specifically utilize the enhanced chemical vapor deposition method at polished silicon slice surface deposition film.

A kind of method at the fluorine-containing carbon-base film of silicon base surface preparation is characterized in that the method carries out according to the following order step:

The A deposition substrate is polished silicon slice, cleans with dehydrated alcohol, acetone and Ultrasonic Cleaners successively;

B adopts enhancement type plasma gas phase deposition equipment, and before thin film deposition, under 4.5～5Pa, under substrate, bias voltage 800～1000V, frequency 20～30KHz, dutycycle are 60～80% times, with the 300sccm argon gas, substrate are carried out plasma clean 30min;

C is for strengthening the bonding force between fluorine-containing amorphous carbon-film and substrate, and under 15～20Pa, substrate bias 1000～1200V, frequency 20～30KHz, dutycycle 60～80% times deposit not fluorocarbon-containing film 10～15min with 10.3sccm methane, 20sccm hydrogen;

D is under 15Pa, and base bias voltage 1000～1200V, frequency 20～30KHz dutycycle 60～80% times deposit fluorocarbon-containing film, condition 1sccm tetrafluoro-methane, 10.3sccm methane, 20sccm hydrogen.

Utilize x-ray photoelectron power spectrum (XPS), Fourier transform infrared spectroscopy (FTIR) to analyze prepared membrane structure in the present invention.Utilize the UMT-2MT friction wear testing machine to characterize prepared frictional coefficient.Adopt scanning electronic microscope (SEM) and three contourgraphs to characterize the film abrasive conditions.Result shows: successfully prepare fluorine-containing carbon-base film, prepared film has very excellent wear-resistant impairment performance.

The present invention improves the wear-resistant energy of anti-damage of silicon chip by the stable carbon-base film of preparation.This method cost is low, the cycle is short, and is easy and simple to handle, and the film of preparing is fine and close, stable, even, good with substrate caking power, shows excellent wear-resistant invulnerability, is a kind of very promising surface lubrication coating technology.

Embodiment

For a better understanding of the present invention, describe by embodiment.

Embodiment 1:

Take methane as precursor gas, as the main carbon source of fluorocarbon-containing film.

Adopt enhancement type plasma gas phase deposition equipment.

Deposition substrate is polished silicon slice, cleans with dehydrated alcohol, acetone and Ultrasonic Cleaners successively; Before thin film deposition, under 4.5～5.0Pa, under substrate, bias voltage 800～1000V, frequency 20～60KHz, dutycycle are 60～80% times, with the 300sccm argon gas, substrate are carried out plasma clean 30min.For strengthening the bonding force between fluorine-containing amorphous carbon-film and substrate, under 15～20Pa, substrate bias 1000～1200V, frequency 20～60KHz, dutycycle 60～80% times deposit not fluorocarbon-containing film 10～15min with 10.3sccm methane, 20sccm hydrogen.Under 15Pa, base bias voltage 1000～1200V, frequency 20～60KHz dutycycle 60% time, preparation fluorocarbon-containing film (1sccm tetrafluoro-methane, 10.3sccm methane, 20sccm hydrogen).

Embodiment 2:

Take acetylene as the purging body, as the main carbon source of fluorocarbon-containing film.

Adopt enhancement type plasma gas phase deposition equipment.

Deposition substrate is polished silicon slice, cleans with dehydrated alcohol, acetone and Ultrasonic Cleaners in advance; Before thin film deposition, under 4.5～5.0Pa, under substrate, bias voltage 800～1000V, frequency 20～60KHz, dutycycle are 60～80% times, with the 300sccm argon gas, substrate are carried out plasma clean 30min.For strengthening bonding force, under 15～20Pa, substrate bias 1000～1200V, frequency 20～60KHz, dutycycle 60～80% times deposit not fluorocarbon-containing film 10～15min with 10.3sccm methane, 20sccm hydrogen.Under 15Pa, base bias voltage 1000～1200V, frequency 20～60KHz dutycycle 60% time, preparation fluorocarbon-containing film (1sccm tetrafluoro-methane, 10.3sccm acetylene, 20sccm hydrogen).

As shown in table 1, during 15Hz, fluorocarbon-containing film and not fluorocarbon-containing film respectively under load 5N, 10N, 20N, carry out frictional behaviour and investigate.Result shows, compares with fluorocarbon-containing film not, and fluorine-contained film has very excellent tribological property under high load 20N.

Table 1: frictional coefficient under different loads fluorine-containing and not fluorine-containing amorphous carbon-film

Claims (1)

1. method at the fluorine-containing carbon-base film of silicon base surface preparation is characterized in that the method carries out according to the following order step:

The A deposition substrate is polished silicon slice, cleans with dehydrated alcohol, acetone and Ultrasonic Cleaners successively;

B adopts enhancement type plasma gas phase deposition equipment, and before thin film deposition, under 4.5～5Pa, under substrate, bias voltage 800～1000V, frequency 20～30KHz, dutycycle are 60～80% times, with the 300sccm argon gas, substrate are carried out plasma clean 30min;

C is for strengthening the bonding force between fluorine-containing amorphous carbon-film and substrate, and under 15～20Pa, substrate bias 1000～1200V, frequency 20～30KHz, dutycycle 60～80% times deposit not fluorocarbon-containing film 10～15min with 10.3sccm methane, 20sccm hydrogen;

D is under 15Pa, and base bias voltage 1000～1200V, frequency 20～30KHz dutycycle 60～80% times deposit fluorocarbon-containing film, condition 1sccm tetrafluoro-methane, 10.3sccm methane, 20sccm hydrogen.