CN1787203A

CN1787203A - Method for forming shallow slot isolation assembly with composite type lining

Info

Publication number: CN1787203A
Application number: CN 200410089391
Authority: CN
Inventors: 江瑞星; 马惠平
Original assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2004-12-10
Filing date: 2004-12-10
Publication date: 2006-06-14

Abstract

The invention provides a method for forming shallow channel isolating component with combined pad, forming a liner oxidizing layer and a silicon nitride mask on the surface of a semiconductor substrate, using the etching technique to form shallow channels, in sequence depositing a silicon nitride layer and an in situ steam generated (ISSG) oxidizing layer, and finally filling a layer of oxide in the shallow channels, so as to form the shallow channel isolating component. The method can solve the problem of depression, reducing the distorting effect and thus improving the conductivity of the component.

Description

Formation method with shallow slot isolation assembly of composite type lining

Technical field

(shallow trench isolation, formation method STI) are particularly closed the formation method that has the shallow slot isolation assembly of composite type lining a kind of to the present invention relates to a kind of shallow slot isolation assembly.

Background technology

In order to shorten traditional localized oxidation of silicon (local oxidation of silicon, LOCOS) the beak length of technology, improve the integration density of assembly, improved localized oxidation of silicon technology (Modified LOCOS) is attempted with various silicon nitride and cushion thickness combination or is changed the shape of silicon nitride in side wall deposition, to reduce the length of stretching in the beak, but its effect is still limited, and the shallow slot isolation assembly that the isolation structure of therefore present semiconductor subassembly has generally taked effectively to be applied in the following assembly of 0.25 μ m is used as the isolation structure of inter-module.

The method of making shallow slot isolation assembly usually sees also Fig. 1 to Fig. 4.At first as shown in Figure 1, form one deck pad oxide 12 earlier, deposit a silicon nitride layer 14 more thereon, and utilize photoetching process, to be formed with shallow trench 16 on a silicon base 10 surfaces; Subsequently as shown in Figure 2, utilize thermal oxidation method to form a lining oxide layer (liner oxide) 18 on shallow trench 16 surfaces, deposit one deck oxide 20 then, make it fill up shallow trench 16, as shown in Figure 3, and utilize cmp (CMP) to carry out flatening process, remove the unnecessary oxide 20 in surface; At last, etching is removed the silicon nitride layer 14 and the pad oxide 12 on surface, as shown in Figure 4, and to finish the making of shallow slot isolation assembly.

Yet; above-mentioned when forming shallow slot isolation assembly; remove the oxide 20 and lining oxide layer 18 meeting generations depression 22 structures as shown in Figure 4 that makes easily in the step in the shallow slot isolation assembly at pad oxide 12; by the recessed phenomenon that contracts at this lining oxide layer 18 and oxide 20; regular meeting causes the shallow slot isolation assembly corner regions to produce the phenomenon of depression 22; cause the assembly electrical quality to reduce, and in assembly, produce twisted effect, and then cause it electrically bad.

Mirror is arranged at this, the present invention is directed to above-mentioned technical problem, propose a kind of formation method, to solve those shortcomings that prior art is produced because of the corner depression with shallow slot isolation assembly of composite type lining.

Summary of the invention

Main purpose of the present invention is that a kind of formation method with shallow slot isolation assembly of composite type lining is being provided, it utilizes the original position steam to produce (In Situ Steam Generation, ISSG) oxidation technology is made the composite type lining in the irrigation canals and ditches, improves the problem of isolation oxide depression with the material behavior of utilizing ISSG oxide layer excellence.

Another object of the present invention is that a kind of formation method with shallow slot isolation assembly of composite type lining is being provided, can effectively reduce the generation of twisted effect, promote component characteristic (device characteristics) to pass through it, and then obtain preferable electrical quality.

For reaching above-mentioned purpose, the present invention forms a pad oxide and a silicon nitride mask layer earlier earlier in the semiconductor substrate; Utilize a patterning photoresist layer to be mask again, this silicon nitride mask layer of etching, pad oxide and substrate to form shallow trench, are then removed this patterned mask layer; Then, form a silicon nitride layer and an original position steam in regular turn on the shallow trench surface and produce (ISSG) oxide layer; At last, form one deck oxide in substrate, make it fill up this shallow trench, then remove this unnecessary oxide of substrate surface, silicon nitride layer, silicon nitride mask layer and pad oxide, to form shallow slot isolation assembly by this.

The formation method of shallow slot isolation assembly provided by the invention, in order to when forming the shallow trench barrier assembly, the electrical bad problem that can avoid shallow trench barrier assembly corner depression to be caused, and the silicon nitride layer that utilizes the CVD technology to form produces (In Situ Steam Generation with utilizing the original position steam, ISSG) structural design of the ISSG oxide layer of oxidation technology making, can effectively prevent the generation of depressed phenomenon, and reduce the generation of twisted effect thus, and then reach the effect of promoting component characteristic and electrical quality.

Description of drawings

Further specify architectural feature of the present invention and beneficial effect thereof below in conjunction with preferred embodiment and accompanying drawing.

Fig. 1 to Fig. 4 is respectively each step structure cutaway view of common making shallow slot isolation assembly.

Fig. 5 to Fig. 9 is respectively each step structure cutaway view of common making shallow slot isolation assembly.

Label declaration

10 substrates, 12 pad oxides

14 silicon nitride layers, 16 shallow trench

18 lining oxide layers, 20 oxides

30 pad oxides of the semiconductor-based ends 32

34 silicon nitride mask layers, 36 patterning photoresist layer

38 shallow trench, 40 silicon nitride layers

42ISSG oxide layer 44 oxides

46 shallow slot isolation assemblies

Embodiment

Usually because of the depressed phenomenon in the shallow slot isolation structure, cause the generation of twisted effect, and then make assembly electrically relatively poor.And the present invention utilizes formed silicon nitride layer of shallow trench sidewall and original position steam to produce (In Situ Steam Generation, ISSG) oxide layer is as composite type lining, improve common disappearance, cave in and twisted effect to avoid producing, and obtain electrical preferably simultaneously.

Fig. 5 to Fig. 9 is that a preferred embodiment of the present invention is at each step structure cutaway view of making shallow slot isolation assembly, as shown in the figure, the disclosed method of the present invention is to include the following step: as shown in Figure 5, semiconductor substrate 30 is provided earlier, and utilize chemical vapour deposition technique to form a pad oxide (pad oxide) 32 on this surface, semiconductor-based ends 30, it is usually by the makers-up of silicon dioxide institute, deposits a silicon nitride mask layer 34 again on pad oxide 32 surfaces again.

Then, silicon nitride mask layer 34 surface on the semiconductor-based end 30 form a patterning photoresist layer 36, and be mask (Mask) with this patterning photoresist layer 36, utilize general lithographic technique, etching is removed not silicon nitride mask layer 34, the pad oxide 32 and the semiconductor-based end 30 of overlay pattern photoresist layer 36, as shown in Figure 6, the silicon nitride layer 34 that will expose, pad oxide 32 can form shallow trench 38 after removing with the semiconductor-based end 30 in the semiconductor-based end 30.After etching formation shallow trench 38, remove this patterning photoresist layer 36.

Then carry out the making step of composite type lining, see also shown in Figure 7ly, utilize the chemical vapor deposition (CVD) technology, form silicon nitride layers 40 on the semiconductor-based end 30 and shallow trench 38 surfaces, with usefulness as insulation protection; Utilize the ISSG oxidation technology to form an ISSG oxide layer 42 on silicon nitride layer 40 surfaces of shallow trench 38 two sides again; The structural design of formed silicon nitride layer 40 and ISSG oxide layer 42 is to prevent the generation of caving in the semiconductor-based end 30 of these shallow trench 38 sidewall edge.

Then, as shown in Figure 8, utilize high-density plasma deposition (High Density Plasma, HDP) mode, on the semiconductor-based end 30, form one deck oxide 44, make oxide 44 fill up this shallow trench 38, and cover ISSG oxide layer 42 surfaces fully, by cmp technology (CMP) oxide 44 is carried out a flatening process again, make its flattening surface.

At last, utilize cmp or electricity slurry etching mode, remove unnecessary oxide 44, ISSG oxide layer 42, silicon nitride layer 40, the silicon nitride mask layer 34 and pad oxide 32 in surface, the semiconductor-based ends 30, to form shallow slot isolation assembly 46 as shown in Figure 9.

Above-described embodiment only is for technological thought of the present invention and characteristics are described, its purpose makes the personage who has the knack of this skill can understand content of the present invention and is implementing according to this, when can not with qualification claim of the present invention, promptly the equalization of doing according to disclosed spirit generally changes or modifies, and must be encompassed in the claim of the present invention.

Claims

1, a kind of formation method with shallow slot isolation assembly of composite type lining, its silicon comprises the following steps:

The semiconductor substrate is provided, and is to deposit a pad oxide and a silicon nitride mask layer in regular turn on it;

Form a patterning photoresist layer at this substrate surface;

With this patterning photoresist layer is mask, and this silicon nitride mask layer of etching, pad oxide and this substrate to form shallow trench, are then removed this patterning photoresist layer;

On this semiconductor-based end, form a silicon nitride layer, make it cover the surface of this shallow trench;

Utilize the original position steam to produce (ISSG) oxidation technology, form an ISSG oxide layer and cover this interior silicon nitride layer surface of this shallow trench; And

Form one deck oxide on this semiconductor-based end, make it fill up this shallow trench, then remove this unnecessary oxide of this semiconductor-based basal surface, this silicon nitride layer, silicon nitride mask layer and this pad oxide, to form shallow slot isolation assembly.

2, the formation method with shallow slot isolation assembly of composite type lining according to claim 1, it is characterized in that: described pad oxide is made up of silica.

3, the formation method with shallow slot isolation assembly of composite type lining according to claim 1 is characterized in that: described silicon nitride layer is to utilize chemical vapour deposition technique to form.

4, the formation method with shallow slot isolation assembly of composite type lining according to claim 1 is characterized in that: the mode that forms this oxide is to utilize high-density electric slurry sedimentation (HDP) to form.

5, the formation method with shallow slot isolation assembly of composite type lining according to claim 1 is characterized in that: after the step that forms this oxide, utilize cmp technology (CMP) to carry out a flatening process.