CN100505151C

CN100505151C - Method for extending use life of reaction cavity in plasma etching system

Info

Publication number: CN100505151C
Application number: CNB200610028977XA
Authority: CN
Inventors: 张胜凯; 黄文助; 杨涛; 刘芳文; 杨利; 许进; 黄海; 季鹏联; 曾最新; 蒋广平; 蓝仁隆; 张仲荣
Original assignee: Semiconductor Manufacturing International Shanghai Corp
Current assignee: Semiconductor Manufacturing International Shanghai Corp; Semiconductor Manufacturing International Beijing Corp
Priority date: 2006-07-14
Filing date: 2006-07-14
Publication date: 2009-06-24
Anticipated expiration: 2026-07-14
Also published as: CN101106069A

Abstract

Response chamber is an important part in plasma etching equipment. The invention provides a method for prolonging service life of the upper response chamber in decoupling plasma source metal etching equipment. The invention prolongs service life of the upper response chamber through providing special coverage on the parts in the upper response chamber that are likely to be damaged by plasma. Meanwhile, the wall of the upper response chamber is unlikely to be damaged under the protection of the coverage ring, so the particles leading to product flaws may eliminated, thus enhancing output rate of high-quality products in the subsequent production.

Description

Prolong the method in useful life of reaction chamber in the plasma etching system

Technical field

The present invention relates to the chemical mechanical milling tech in the semiconductor fabrication process, be specifically related to a kind of method that reduces pattern depression in the chemical mechanical planarization process.

Background technology

Plasma etching is one of critical process during integrated circuit is made, its objective is intactly mask pattern is copied to silicon chip surface, its scope contains the control of front end CMOS grid (Gate) size, and the etching of the etching of rear end metallic aluminium and through hole (Via) and raceway groove (Trench).Today the neither one integrated circuit (IC) chip can finish lacking under the plasma etching technology situation.Account for 10%～12% proportion in the equipment investment of making an investment in the chip factory of etching apparatus generally speaking, its technological level and appointed condition will directly have influence on the advance of end product quality and production technology.

The principle of plasma etching can brief overview be: under low pressure, reacting gas is subjected to exciting of radio-frequency power, produce ionization and form plasma, plasma is made up of charged electronics and ion, gas in the reaction cavity is under the bump of electronics, except being transformed into ion, can also absorb energy and form a large amount of active group (Radicals), active reactive group and etched material surface generation chemical reaction also form volatile reaction product, reaction product breaks away from etched material surface, and is extracted out cavity by vacuum system.In plasma etching equipment, reaction chamber is crucial parts, because the intrinsic mode of operation of plasma etching, when board moves, its reaction chamber inner surface equally can be by plasma damage, especially near the gas access, point discharge effect because of plasma, impaired herein the most serious, produce the problem of two aspects like this, at first because reactor wall is impaired, the fine particle of its generation has influence on the etched material in the reaction chamber easily, form defective thereon, thereby bring negative effect for subsequent technique and yield; On the other hand, reaction chamber just need be changed to guarantee the normal function of board according to the extent of damage after using to a certain degree.

In view of present scale of mass production and high-end process requirements, the used high energy electromagnetic field of metal etch link (RF) can quicken to shorten the useful life of reaction chamber (Upper Chamber) on the important composition parts that for example divide coupling formula plasma source metal etch board (DPS METAL TOOL) during integrated circuit was made.According to the rough estimate to the semiconductor wafer factories of a scale of mass production, these parts need more be exchanged treaties 20 every year.The described reaction chamber parts of going up belong to the high running stores of cost, and frequent replacing must cause production cost to go up.

Summary of the invention

For the useful life of reaction chamber on prolonging in the branch coupling formula plasma source metal etch board, and reduce the defective that causes etched object in the etching process owing to reaction chamber is impaired, propose the present invention.

One object of the present invention is, provide a kind of the prolongation to go up the reaction chamber method in useful life in the branch coupling formula plasma source metal etch board, by in the last reaction chamber easily the part of subject plasma infringement the covering of special material is provided, make and obtain prolongation in useful life of reaction chamber.

Another object of the present invention is, provides a kind of air inlet of going up reaction chamber useful life that is used to prolong that designs according to above-mentioned covering to cover ring set.

As introducing in the background technology, for a minute coupling formula plasma source metal etch board, because the point discharge effect of plasma, the active reactive group reaction that air inlet place chamber wall of reaction chamber forms with the institute gas that enters especially easily on it and suffering damage, and the particulate of this kind course of damage generation more can further cause product defects.

The present invention proposes solution in view of the above, method is that the impaired easily position of reaction chamber increases the suitable polytetrafluoroethylmaterial material or the covering of ceramic material on described, this covering can stop under the high energy electromagnetic field effect damage to last reaction chamber inner surface gas feed place material effectively, and covering itself bring particulate can't for last reaction chamber internal milieu.

According to above scheme, the present invention proposes a kind of described polytetrafluoroethylene or ceramic ring set of going up the reaction chamber air inlet that be used for, can be used as above-mentioned covering.The structure of this covering ring set comprises:

Middle round-meshed annular gasket;

The cylindrical protrusion structure is that the basis extends upward with the circular hole edge in the middle of the annular gasket, the plane vertical connection of itself and annular gasket, and the circular hole of cylindrical shape and annular gasket adapts.

Said structure is formed in one, and the employing polytetrafluoroethylene is a material, and the last reaction chamber air inlet port size of the size of whole ring set and branch coupling formula plasma source metal etch board adapts.

During the above-mentioned covering ring set used, partly insert the described air inlet (air inlet has the tubular space that suitable cylindrical shape is inserted) of going up reaction chamber with the cylindrical protrusion on it, the inwall that props up reaction chamber to annular gasket can use board by common mode.

The invention has the advantages that:

1, use the solution of the present invention, the described easily impaired part of reaction chamber that goes up promptly all is capped the ring set protection near the air inlet, be unlikely in use to be lost to too quickly the stage that can not use, and will greatly prolong therefore whole useful life of going up reaction chamber;

2, because last reactor wall is difficult for impairedly covering under the ring set protection, also just be not easy to produce the particulate that can cause product defects, like this to subsequent technique so that the product yield all has lifting;

3, covering ring set of the present invention is very easy to loading and unloading, and its material is polytetrafluoroethylene, is easy to clean, and this also is vital for plasma etching system, because the quality of cleaning effect directly influences the performance of whole etching machine.

For be more readily understood purpose of the present invention, feature with and advantage, below conjunction with figs. and embodiment are described in detail the present invention.

Description of drawings

The accompanying drawing that comprises among the application is a component part of specification, and accompanying drawing and specification and claims one are used from explanation flesh and blood of the present invention, are used for understanding better the present invention.

Fig. 1 is an air inlet cover ring nested structure schematic diagram provided by the present invention, and wherein 1 is that whole air inlet covers ring set, and 11 is middle round-meshed annular gasket, and 12 is the cylindrical protrusion structure;

Fig. 3 a is the covering ring set schematic diagram that places after board uses;

Fig. 3 b is for covering the ring set schematic diagram through shown in Fig. 3 a that cleans;

Figure 4 shows that within a period of time to model to be TOOL---the board of BEMEA02B is monitored the curve chart that particulate obtains in reaction cavity on it when high energy electromagnetic field opening;

Figure 5 shows that within a period of time to model to be TOOL---the board of BEMEA02B is monitored the curve chart that particulate obtains in reaction cavity on it when high energy electromagnetic field closure state;

Figure 6 shows that within a period of time to model to be TOOL---the critical process gas Cl of the board of BEMEA02B ₂, BCl ₃Carry out the resulting curve chart of flow monitoring;

Figure 7 shows that within a period of time to model to be TOOL---the critical process gas Cl of the board of BEMEA02B ₂, BCl ₃Carry out the resulting curve chart of flow monitoring;

Fig. 8 a has shown the X-ray scanning formula electron microscope picture of using actual product behind the present invention;

Fig. 8 b has shown and has used that the photoresist of actual product keeps the situation picture behind the present invention; And

Fig. 8 c has shown behind application the present invention side wall (Sidewall) profile situation in the actual product.

Description of reference numerals

1	Cover ring set
1	Cover ring set	2	Reaction chamber air inlet position
3	The inwall of reaction chamber	2	Reaction chamber air inlet position
3	The inwall of reaction chamber	11	Middle round-meshed annular gasket
12	The cylindrical protrusion structure	11	Middle round-meshed annular gasket

Embodiment

In order to understand technology of the present invention better, be described further below in conjunction with specific embodiments of the invention, but it does not limit the present invention.

Embodiment 1

The covering ring set that is used for reaction chamber air inlet on the branch coupling formula plasma metal etch board

As shown in Figure 1, air inlet covering ring set 1 of the present invention comprises:

Middle round-meshed annular gasket 11;

Cylindrical protrusion structure 12 is that the basis extends upward with the circular hole edges in the middle of the annular gasket 11, the plane vertical connection of itself and annular gasket, and the circular hole of cylindrical shape and annular gasket adapts.

The structure that covers ring set is formed in one, adopting polytetrafluoroethylene or pottery is material, the last reaction chamber air inlet port size of the size of whole ring set and branch coupling formula plasma source metal etch board adapts, the external diameter that covers ring set is 32～40mm, and the thickness of its annular gasket 11 and cylindrical protrusion structure 12 is 4～8mm.

Use this cover ring be placed in plasma source metal etch board on during reaction chamber air inlet position 2, in the tubular space in the air inlet of the described upward reaction chamber of 12 insertions of the cylindrical protrusion part on it, the inwall 3 that props up reaction chamber to annular gasket 11 can use board by common mode.Fig. 2 a～Fig. 2 c has shown front view, vertical view and the profile when this covering ring set is installed in air inlet respectively.。

Embodiment 2

Among this embodiment, the actual effect behind application the present invention every monitoring and analysis have been done.

Accompanying drawing 3a is the covering ring set schematic diagram that places after board uses, and Fig. 3 b can see the respond well of cleaning for covering the ring set schematic diagram through shown in Fig. 3 a that cleans, and the material of this ring set is easy to clean.

Fig. 4 and shown in Figure 5 being respectively within a period of time model are TOOL---the curve chart that particulate obtains in reaction cavity on it is opened/monitored when closing state to the board of BEMEA02B at the high energy electromagnetic field, ordinate among the figure is represented particle number, abscissa is represented Measuring Time, the particulate number average of illustrated each time surpasses the number that gauge wire limited, and this shows that polytetrafluoroethylene of the present invention covers ring set itself and can not bring particulate in the cavity of last reaction chamber.

Fig. 6 and shown in Figure 7 being respectively within a period of time model are TOOL---the critical process gas Cl of the board of BEMEA02B ₂, BCl ₃Carry out the resulting curve chart of flow monitoring, ordinate is represented gas flow among the figure, abscissa is a Measuring Time, the gas flow that illustrated each time records is all uninfluenced, within specification, this shows that polytetrafluoroethylene of the present invention covers ring set itself and can not influence the required gas flow of technology.

Fig. 8 a～8c has shown the X-ray scanning formula electron microscope picture of using actual product behind the present invention respectively, photoresist keeps situation, and side wall (Sidewall) profile situation, the result shows that the critical size of metal wire and side wall (Sidewall) profile are all very normal, also promptly use the present invention and can not produce any harmful effect to existing processes.

Claims

1, a kind of method in useful life of reaction chamber in the plasma etching system that prolongs is characterized in that, before using described reaction chamber, its air inlet position covers the chamber wall with the covering that polytetrafluoroethylene or pottery constitute, and then uses reaction chamber.

2, the method in reaction chamber useful life in the prolongation plasma etching system as claimed in claim 1 is characterized in that described covering is a kind of covering ring set, and it comprises array structure down:

Middle round-meshed annular gasket;

3, the method in reaction chamber useful life in the prolongation plasma etching system as claimed in claim 2 is characterized in that described all structures of covering ring set are formed in one.

4, the method in reaction chamber useful life in the prolongation plasma etching system as claimed in claim 2 is characterized in that, it is material that described covering ring set adopts polytetrafluoroethylene.