Improve method and the method for manufacturing integrated circuit of shallow trench isolation process metallic pollutionTechnical field
The present invention relates to field of semiconductor manufacture, it is more particularly related to one improves shallow trench isolation processThe method of metallic pollution and have employed the IC manufacturing side of method of this improvement shallow trench isolation process metallic pollutionMethod.
Background technology
STI (Shallow Trench Isolation, improve shallow trench isolation) technique along with integrated circuit live width byGradually reducing the problem more and more facing filling cavity, the mode of traditional pure deposition can cause the generation in cavity.And new workSkill is introducing NF3While etching, the problem that have also been introduced metallic pollution, and these metals especially heavy metal (Cr, Ti, Zn,Cu, Fe, Mn) to cause the reduction of product yield, wherein heavy metal Cr after ultra-specification be one of major influence factors.
It is therefore desirable to it is possible to a kind of method that can effectively improve shallow trench isolation process metallic pollution is provided.
Summary of the invention
The technical problem to be solved is for there is drawbacks described above in prior art, it is provided that one can be effectiveThe method that ground improves shallow trench isolation process metallic pollution.
In order to realize above-mentioned technical purpose, according to the present invention, it is provided that one improves shallow trench isolation process metallic pollutionMethod, including:
First step: be arranged in by silicon chip in shallow ditch groove separation process board, wherein uses electrostatic chuck to fix silicon chip；
Second step: while performing shallow ditch groove separation process, lead to inertia on the surface relative with silicon chip of electrostatic chuckGas, to take away the heavy metal element of electrostatic chuck surface.
Preferably, the described method improving shallow trench isolation process metallic pollution also includes third step: utilize vacuum pumpTake the air in shallow ditch groove separation process board away.
Preferably, heavy metal element is Cr element.
Preferably, noble gas is He gas.
Preferably, shallow ditch groove separation process includes that plasma-based is bombarded.
Preferably, shallow ditch groove separation process includes NF3Etching.
Preferably, shallow ditch groove separation process includes depositing operation.
In order to realize above-mentioned technical purpose, according to the present invention, additionally provide one have employed above-mentioned improve shallow trench isolationThe method for manufacturing integrated circuit of the method for processing procedure metallic pollution.
In the present invention, when technique performs, by leading to the He of certain flow at electrostatic chuck surface, by electrostatic chuck tableThe Cr element in face blows away, and is taken away by vacuum pump, thus reduces the purpose that metal Cr pollutes.
Accompanying drawing explanation
In conjunction with accompanying drawing, and by with reference to detailed description below, it will more easily the present invention is had more complete understandingAnd its adjoint advantage and feature is more easily understood, wherein:
Fig. 1 schematically shows the side improving shallow trench isolation process metallic pollution according to the preferred embodiment of the inventionThe flow chart of method.
It should be noted that accompanying drawing is used for illustrating the present invention, and the unrestricted present invention.Note, represent that the accompanying drawing of structure canCan be not necessarily drawn to scale.Further, in accompanying drawing, same or like element indicates same or like label.
Detailed description of the invention
In order to make present disclosure more clear and understandable, below in conjunction with specific embodiments and the drawings in the present inventionAppearance is described in detail.
The present inventor, by analyzing the composition of shallow ditch groove separation process board internal part, finds its critical componentElectrostatic chuck surface composition contains the Cr of 5%, and electrostatic chuck inherently has adsorption, its surface because plasma-based bombardment andNF3The Cr element etched and separate out, will remain in electrostatic chuck surface because of the absorption of electrostatic chuck, all the time thus at silicon chipDuring transmission, Cr element is kicked up, and then pollutes silicon chip.
Correspondingly, the present invention proposes, silicon chip deposits when, by leading to the He of certain flow at electrostatic chuck surface,The Cr element of electrostatic chuck surface is blown away, and is taken away by vacuum pump, thus reduce the purpose that metal Cr pollutes.
Fig. 1 schematically shows the side improving shallow trench isolation process metallic pollution according to the preferred embodiment of the inventionThe flow chart of method.
As it is shown in figure 1, the method improving shallow trench isolation process metallic pollution according to the preferred embodiment of the invention includes:
First step S1: be arranged in by silicon chip in shallow ditch groove separation process board, wherein uses electrostatic chuck to fix silicon chip；
Second step S2: while performing shallow ditch groove separation process, lead to lazy on the surface relative with silicon chip of electrostatic chuckProperty gas, to take away the heavy metal element (Cr element) of electrostatic chuck surface；
Such as, noble gas is He gas.
Such as, shallow ditch groove separation process includes that plasma-based is bombarded.
Such as, shallow ditch groove separation process includes NF3Etching.
Such as, shallow ditch groove separation process includes depositing operation.
Third step S3: utilize vacuum pump to take the air in shallow ditch groove separation process board away.
Thus, as it has been described above, when technique performs, by leading to the He of certain flow at electrostatic chuck surface, electrostatic is inhaledThe Cr element of panel surface blows away, and is taken away by vacuum pump, thus reduces the purpose that metal Cr pollutes.
Wherein, second step S2 and third step S3 can synchronize to carry out.
Furthermore, it is necessary to explanation, unless stated otherwise or point out, otherwise the term in description " first ", " theTwo ", " the 3rd " etc. describe be used only for distinguishing in description each assembly, element, step etc. rather than for representing eachLogical relation between assembly, element, step or ordering relation etc..
Although it is understood that the present invention discloses as above with preferred embodiment, but above-described embodiment being not used toLimit the present invention.For any those of ordinary skill in the art, without departing under technical solution of the present invention ambit,Technical solution of the present invention is made many possible variations and modification by the technology contents that all may utilize the disclosure above, or is revised asEquivalent embodiments with change.Therefore, every content without departing from technical solution of the present invention, according to the technical spirit pair of the present inventionAny simple modification made for any of the above embodiments, equivalent variations and modification, all still fall within the scope of technical solution of the present invention protectionIn.