阅读说明：本技术 半导体成膜apcvd机台工艺腔体干湿结合的保养方法 (Maintenance method for dry-wet combination of semiconductor film forming APCVD machine process cavity ) 是由 翁剑峰 贺贤汉 于 2021-05-31 设计创作，主要内容包括：本发明公开了半导体成膜APCVD机台工艺腔体干湿结合的保养方法,主要是在普通氮气加氢氟酸腐蚀干法吹扫的基础上在前期加入了独特的湿法工艺,使得氢氟酸在湿法过程中能腐蚀70％的沉积在工艺腔体内的SiO-2粉的残余量,再结合原有的干法腐蚀；这样就能使得沉积在工艺腔体内的SiO-2粉被清除得更为彻底；这种干湿结合的保养方法是该机器的保养首创,并通过反复的实验,成果显著。(The invention discloses a maintenance method for dry-wet combination of a semiconductor film forming APCVD machine process cavity, which is mainly characterized in that a unique wet process is added in the early stage on the basis of common nitrogen-hydrogenated hydrofluoric acid corrosion dry-method purging, so that 70% of hydrofluoric acid can corrode SiO deposited in the process cavity in the wet process 2 The residual amount of the powder is combined with the original dry etching; this enables the deposition of SiO in the process chamber 2 The powder is removed more thoroughly; the maintenance method of the dry-wet combination is the first maintenance of the machine, and the results are remarkable through repeated experiments.)

1. The maintenance method of the dry-wet combination of the semiconductor film forming APCVD machine process cavity is characterized in that: the method comprises the following specific steps:

preparing a maintenance device, wherein the maintenance device comprises a special nozzle for dry etching;

step two, wet etching: laying dust-free cloth on a floor in a machine process cavity, then pouring hydrofluoric acid according to the dosage of 140-180 ml per square meter so that the dust-free cloth uniformly contains a certain amount of hydrofluoric acid, then covering a special nozzle for corrosion, and carrying out hydrofluoric acid wet etching, wherein the wet etching time is at least 5 hours;

step three, removing the special nozzle for corrosion after wet corrosion is finished, slightly cleaning the process cavity, removing the dust-free cloth, attaching a small amount of purified water on a metal floor of a purification layer at the bottom layer of the machine process cavity according to the dosage of 140 plus 180 milliliters per square meter, and covering the special nozzle for corrosion to perform dry sweeping corrosion by using a pipeline for cleaning the metal track by using the special dry corrosion method for the machine;

and fourthly, after the dry-method blowing and corroding are carried out for at least 15 hours, the dry-method blowing is turned off, the special nozzle is removed, and the process cavity is maintained.

2. The method of claim 1, wherein the method comprises the steps of: the process chamber maintenance in the fourth step comprises the following specific steps:

step 1, polishing a purification layer metal floor of a process cavity by using a coarse sand skin, and polishing residual crystals on the purification layer metal floor into powder;

step 2, cleaning powdery residues by using a vacuum cleaner or vacuum sweeping;

3, using a direct-current drill with a 0.8 mm high-strength small drill bit to perform through holes on the process nitrogen holes on the metal floor of the purification layer;

and 4, dipping the dust-free cloth into industrial alcohol to thoroughly and finely clean the periphery of the purification layer metal floor and the process cavity.

3. The method of claim 1, wherein the method comprises the steps of: and step two, before the hydrofluoric acid is splashed, a plurality of pieces of purification cloth are overlapped and then placed at the edges of two sides of the floor right below the installation position of the special nozzle.

4. The method of claim 1, wherein the method comprises the steps of: and in the second step, before the hydrofluoric acid is splashed, the plane between the process cavities of the adjacent machine tables is tiled by the purification cloth.

5. The method of claim 1, wherein the method comprises the steps of: the roughness of the floor in the machine technological cavity maintained by the dry-wet combined maintenance method is below 8.41.

Technical Field

The invention belongs to the field of semiconductor silicon wafer film forming processing, and particularly relates to a dry-wet combined maintenance method for a semiconductor film forming APCVD machine process cavity.

Background

In general, a semiconductor normal pressure film forming process is to deposit a layer of polycrystalline silicon film on the surface of a semiconductor silicon wafer by a chemical vapor deposition method under normal pressure and high temperature state in a process cavity and through thermal decomposition of silane, and a great amount of SiO is deposited in the process cavity after a certain process time is accumulated along with the process time₂The powder and the crystal particles can not only pollute the bottom cavity of the process cavity of the machine, so that the small holes for blowing nitrogen gas on the bottom PURGE FLOOR in the process cavity of the machine such as WAKTING-JOHNSON can be blocked by the crystal particles, thereby not only influencing the normal process in the process, but also lifting the particles in the process to influence the effect after the whole film forming, and ensuring that the defective products and the rejection rate are always high.

The existing WATKING-JOHNSON (APCVD) machine maintenance method is only according to the conventional hydrofluoric acid dry methodThe etching is still applicable to the low film thickness process due to the difference of the film thickness of the formed film of the semiconductor silicon wafer, and the SiO remained in the high film thickness process₂The particles are more and thick, the dry etching and purging effect of the common nitrogen and hydrofluoric acid gas is not ideal, the dry etching and cleaning can not meet the requirements of various semiconductor processes carried by a machine, the process period can be obviously shortened, and the productivity of the machine and the utilization rate of equipment are seriously influenced.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a dry-wet combined maintenance method for a process cavity of a semiconductor film forming APCVD machine, which is used for efficiently maintaining APCVD (atmospheric pressure chemical vapor deposition) machines such as WAKTING-JOHNSON through practical and effective dry-wet combined maintenance, thereby recovering the clean environment before the machine is processed, greatly improving the production efficiency and practically solving the problem of poor field semiconductor silicon wafer process.

The technical scheme of the invention is as follows: the maintenance method of the dry-wet combination of the process cavity of the semiconductor film forming APCVD machine comprises the following specific steps:

preparing a maintenance device, wherein the maintenance device comprises a special nozzle for dry etching;

step two, wet etching: laying dust-free cloth on a floor in a machine process cavity, then pouring hydrofluoric acid according to the dosage of 140-180 ml per square meter so that the dust-free cloth uniformly contains a certain amount of hydrofluoric acid, then covering a special nozzle for corrosion, and carrying out hydrofluoric acid wet etching, wherein the wet etching time is at least 5 hours;

step three, removing the special nozzle for corrosion after wet corrosion is finished, slightly cleaning the process cavity, removing the dust-free cloth, attaching a small amount of purified water on a metal floor of a purification layer at the bottom layer of the machine process cavity according to the dosage of 140 plus 180 milliliters per square meter, and covering the special nozzle for corrosion to perform dry sweeping corrosion by using a pipeline for cleaning the metal track by using the special dry corrosion method for the machine; it should be noted that before dry etching, a small amount of water must be sprayed on the PURGE FLOOR, and the small amount of water can contain a small proportion of hydrofluoric acid after dry purging the hydrofluoric acid gas, so that the residues on the FLOOR and the silicon powder in the process nitrogen holes on the FLOOR can be effectively and continuously etched.

And fourthly, after the dry-method blowing and corroding are carried out for at least 15 hours, the dry-method blowing is turned off, the special nozzle is removed, and the process cavity is maintained.

Further, the step four of maintaining the process chamber comprises the following specific steps:

step 1, polishing a purification layer metal floor of a process cavity by using a coarse sand skin, and polishing residual crystals on the purification layer metal floor into powder;

step 2, cleaning powdery residues by using a vacuum cleaner or vacuum sweeping;

3, using a direct-current drill with a 0.8 mm high-strength small drill bit to perform through holes on the process nitrogen holes on the metal floor of the purification layer; in order to prevent particles from blocking the pores.

And 4, dipping the dust-free cloth into industrial alcohol to thoroughly and finely clean the periphery of the purification layer metal floor and the process cavity.

Further, in the second step, before the hydrofluoric acid is splashed, a plurality of pieces of purification cloth are overlapped and then placed at the two side edges of the floor right below the installation position of the special nozzle. Prevent too much hydrofluoric acid splashed in the wet process from flowing into the machine and corroding the machine.

Further, in the second step, before the hydrofluoric acid is splashed, the plane between the process cavities of the adjacent machine tables is tiled by the purification cloth. Prevent hydrofluoric acid from splashing on the table top to corrode the machine table in a wet method.

Furthermore, the roughness of the floor in the machine process cavity maintained by the dry-wet combined maintenance method is below 8.41.

The invention has the beneficial effects that: the invention mainly adds a unique wet process on the basis of the dry blowing of the common nitrogen-hydrofluoric acid hydrogenation corrosion, so that 70 percent of the SiO deposited in the process cavity can be corroded by hydrofluoric acid in the wet process₂And combining the residual amount of the powder with the original dry etching. Thus, it isCan make SiO deposited in the process chamber₂The powder is removed more thoroughly. The maintenance method of the dry-wet combination is the first maintenance of the machine, and the results are remarkable through repeated experiments.

It should be noted that before dry etching, a small amount of water must be sprayed on the PURGE FLOOR, and the small amount of water can contain a small proportion of hydrofluoric acid after dry purging the hydrofluoric acid gas, so that the residues on the FLOOR and the silicon powder in the process nitrogen holes on the FLOOR can be effectively and continuously etched.

By increasing the early stage hydrofluoric acid wet etching, the consumption of the hydrofluoric acid of 140 ml per square meter and 180 ml per square meter is increased, the cost is extremely low, and the effect is very good.

The productivity of the equipment and the stability of the later process are ensured, the on-site poor rejection rate is reduced, and the obvious economic benefit is generated.

Detailed Description

The maintenance method of the dry-wet combination of the process cavity of the semiconductor film forming APCVD machine comprises the following specific steps:

first, a personal care device for maintenance is prepared, including: special nozzle for dry etching, special Teflon corrugated pipe, self-made brush for cleaning and special Teflon air pipe.

Wet etching: dustless cloth is laid on the floor in the machine process cavity, and a plurality of pieces of purification cloth are overlapped and then placed at the edges of two sides of the floor right below the installation position of the special nozzle. Prevent too much hydrofluoric acid splashed in the wet process from flowing into the machine and corroding the machine. The planes between the adjacent machine process cavities are tiled by the purification cloth. After the labor protection article for protection is worn, hydrofluoric acid is poured into the dust-free cloth according to the dosage of 160 milliliters per square meter, so that the dust-free cloth uniformly contains a certain amount of hydrofluoric acid, then a special nozzle for corrosion is covered, hydrofluoric acid wet corrosion is carried out, and the wet corrosion time is at least 5 hours.

After wet etching is finished, the special etching nozzle is removed, the process cavity is slightly cleaned, the dust-free cloth is removed, a small amount of purified water is attached to a PURGE FLOOR metal FLOOR at the bottom layer of the cavity according to the usage amount of 160 milliliters per square meter, and the special etching nozzle is covered to perform dry purging etching by using a pipeline for cleaning a metal track in a dry etching way special for a WAKTING-JOHNSON machine. It should be noted that before dry etching, a small amount of water must be sprayed on the PURGE FLOOR, and the small amount of water can contain a small proportion of hydrofluoric acid after dry purging the hydrofluoric acid gas, so that the residues on the FLOOR and the silicon powder in the process nitrogen holes on the FLOOR can be effectively and continuously etched.

After the dry-method blowing and etching are carried out for 16 hours, the dry-method blowing and etching are closed, a special nozzle for the dry-method etching is removed, and the process cavity is maintained. The specific maintenance steps are as follows:

the PURGE FLOOR metal FLOOR of the process chamber was sanded with a grit skin. SiO on metal floor after wet and dry corrosion₂Most of the residue has been eroded and purged clean. The remainder was easily removed when the crystals became powdery upon grinding of the coarse sand skin. Then cleaning the SiO left after polishing₂The crystallization residue is cleaned by a vacuum cleaner or vacuum sweep. The process nitrogen holes on the PURGE FLOOR metal FLOOR were then perforated with a DC drill with a 0.8 mm high strength small bit to prevent particles from plugging the holes. And finally, dipping industrial alcohol in dust-free cloth to thoroughly and finely clean the PURGE FLOOR metal FLOOR and the periphery of the process cavity.

The comparison result between the roughness of the floor in the machine process cavity maintained by combining the specific dry and wet methods in this embodiment and the roughness of the floor in the machine process cavity maintained by only using the common dry method is shown in table 1 below.

TABLE 1

The invention mainly adds a unique wet process on the basis of the dry blowing of the common nitrogen-hydrofluoric acid hydrogenation corrosion, so that 70 percent of the SiO deposited in the process cavity can be corroded by hydrofluoric acid in the wet process₂And combining the residual amount of the powder with the original dry etching. This enables the deposition of SiO in the process chamber₂The powder is removed more thoroughly. The maintenance method of the dry-wet combination is the first maintenance of the machine, and the results are remarkable through repeated experiments.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.