CN103066009A

CN103066009A - Technique of filling tungsten plug in through silicon vias (TSV)

Info

Publication number: CN103066009A
Application number: CN2011103172379A
Authority: CN
Inventors: 陈帆; 陈雄斌; 薛凯; 周克然; 潘嘉; 李�浩
Original assignee: Shanghai Hua Hong NEC Electronics Co Ltd
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2011-10-18
Filing date: 2011-10-18
Publication date: 2013-04-24

Abstract

The invention discloses a technique of filling a tungsten plug in through silicon vias (TSV). The method comprises the following steps: forming a contact hole and the TSV on a silicon substrate where an insulating layer is formed; depositing a first liner layer; depositing a first layer of tungsten and completely filling the contact hole; carrying out first etchback and staying on the first liner layer; depositing a second liner layer; depositing a second layer of the tungsten, carrying out second etchback and staying on the second liner layer; repeating a step 6 till that the TSV is completely filled by the tungsten; using a chemical mechanical grinding technology to remove the tungsten on a surface of the insulating layer, the first liner layer and the second liner layer. By using the method of the invention, the TSV and the contact hole can be filled together. The tungsten filling does not need to be performed for the regular contact hole so that the technology is simplified and technology cost is reduced.

Description

Penetrate the process of the filling through hole tungsten plug of silicon

Technical field

The present invention relates to a kind of semiconductor integrated circuit method of manufacturing technology, particularly relate to a kind of process that penetrates the filling through hole tungsten plug of silicon.

Background technology

In some semiconductor device technologies, can need to use the technique of the through hole (Through SiliconVias, TSV) that penetrates silicon.Conventional TSV way is: at first the TSV pattern etching is arrived the needed degree of depth, usually more than 100 microns.Because the degree of depth of required etching is very large, so the size of TSV through hole is all larger, micron dimension normally, such as about 2 microns.But because the depth-to-width ratio of TSV is still very high, so the filling of TSV still needs to adopt the mode of tungsten chemical vapour deposition (CVD) to carry out.But the contact hole size of TSV and conventional semiconductor device design differs greatly, and existing contact hole may be the size of deep-submicron, and such as 0.2 micron～0.3 micron, so little contact hole can't be filled together with TSV.

The way of integrated TSV and contact hole is in the existing technique, at first the TSV etching out, then carries out the tungsten of TSV and fills.The tungsten of TSV is filled and is adopted back the way of carving.Because each tungsten filling thickness is limited, thickness prevents that less than 1 micron the stress of tungsten is to the silicon chip injury usually.Therefore for large-sized TSV, need repeatedly to fill, do returning of a tungsten after each tungsten is filled and carve, rest on the laying titanium nitride of tungsten.After filling up tungsten among the last TSV, by the cmp of tungsten surface remaining tungsten and laying are removed.Then contact hole is carried out photoetching and etching formation figure, and the laying of deposition tungsten and tungsten, then carry out the cmp of tungsten the unnecessary tungsten of silicon chip surface is all removed.To shown in Figure 8, be the schematic diagram in each step of the process of the existing filling through hole tungsten plug that penetrates silicon such as Fig. 1, existing process comprises the steps:

As shown in Figure 1, at first, the silicon substrate 1 that provides a surface to be formed with insulating barrier 2 adopts chemical wet etching technique that described insulating barrier 2 and described silicon substrate 1 are carried out the through hole 3 that etching formation penetrates silicon, and the described through hole 3 that penetrates silicon penetrates described insulating barrier 2 and enters into described silicon substrate 1.

As shown in Figure 2, the laying 4 of deposition tungsten, this laying 4 is generally titanium nitride.

As shown in Figure 3, deposit tungsten layer 5 on described laying 4.The thickness of this tungsten layer 5 prevents that usually less than 1 micron the stress of tungsten is to silicon substrate 1 injury.

As shown in Figure 4, described tungsten layer 5 is returned carve and rest on the described laying 4.

As shown in Figure 5, repeating the tungsten deposit makes the described tungsten layer 5 of formation that the described through hole 3 that penetrates silicon is filled up.

As shown in Figure 6, adopt chemical mechanical milling tech that tungsten and the described laying 4 of described surface of insulating layer are all removed.At last, it is equal with described surface of insulating layer to be filled in the surface of tungsten of the described through hole 3 that penetrates silicon.

As shown in Figure 7, adopt chemical wet etching technique that described insulating barrier 2 etchings are formed contact hole 6, described contact hole 6 is arranged in described insulating barrier 2 and and described silicon substrate 1 Surface Contact.

As shown in Figure 8, and the laying of deposition tungsten and tungsten fills described contact hole 6, adopts chemical mechanical milling tech that the unnecessary tungsten of described surface of insulating layer and the laying of tungsten are removed.

Because contact hole and TSV need to fill respectively in the existing technique, cause process complexity to increase, cost is also high.

Summary of the invention

Technical problem to be solved by this invention provides a kind of process that penetrates the filling through hole tungsten plug of silicon, can realize penetrating the in the lump filling of through hole and the contact hole of silicon, thereby can make work simplification and reduce process costs.

For solving the problems of the technologies described above, the process that penetrates the filling through hole tungsten plug of silicon provided by the invention comprises the steps:

Step 1, the silicon substrate that provides a surface to be formed with insulating barrier adopt chemical wet etching technique that described insulating barrier etching is formed contact hole, and described contact hole is arranged in described insulating barrier and contacts with described surface of silicon; Then, adopt chemical wet etching technique that described insulating barrier and described silicon substrate are carried out the through hole that etching formation penetrates silicon, the described through hole that penetrates silicon penetrates described insulating barrier and enters into described silicon substrate.

Step 2, deposit the first laying, described the first laying are positioned at described contact hole and described sidewall and lower surface and other the regional surface of insulating layer that penetrates the through hole of silicon.

Step 3, on described the first laying deposit ground floor tungsten, described ground floor tungsten is filled described contact hole fully.

Step 4, described ground floor tungsten is carried out the first time return to carve, return the described first time to carve and rest on described the first laying.

Deposit the second laying on the surface of step 5, formation after returning quarter described first time.

Step 6, on described the second laying deposit second layer tungsten; Described second layer tungsten is carried out the second time return to carve, return the described second time to carve and rest on described the second laying.

Step 7, repeating step six until the described through hole that penetrates silicon filled up fully by tungsten.

Step 8, employing chemical mechanical milling tech are all removed the tungsten of the described surface of insulating layer on the described silicon substrate, described the first laying and described the second laying.

Further improvement is, described first laying of deposit is comprised of titanium and the titanium nitride of successively deposit in the step 2, and the thickness of the titanium of described the first laying is The thickness of the titanium nitride of described the first laying is

Further improving is that the thickness of the tungsten of ground floor described in the step 3 is

Further improvement is, the second laying described in the step 5 is titanium nitride, and the thickness of described the second laying is

Further improving is that the thickness of the tungsten of the second layer described in the step 6 is

The inventive method can realize penetrating the in the lump filling of through hole and the contact hole of silicon, does not need to carry out for the contact hole of routine the filling of a tungsten more, thereby can make work simplification and reduce process costs.

Description of drawings

The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments:

Fig. 1 to Fig. 8 is the schematic diagram in each step of process of the existing filling through hole tungsten plug that penetrates silicon;

Fig. 9 is embodiment of the invention method flow diagram;

Figure 10-Figure 17 is the schematic diagram in each step of embodiment of the invention method.

Embodiment

As shown in Figure 9, be embodiment of the invention method flow diagram; To shown in Figure 17, be the schematic diagram in each step of embodiment of the invention method such as Figure 10.

The process that the embodiment of the invention penetrates the through hole 104 filling tungsten plugs of silicon comprises the steps:

Step 1, as shown in figure 10, the silicon substrate 101 that provides a surface to be formed with insulating barrier 102, adopt chemical wet etching technique that described insulating barrier 102 etchings are formed contact hole 103, described contact hole 103 is arranged in described insulating barrier 102 also and described silicon substrate 101 Surface Contacts; Then, adopt chemical wet etching technique that described insulating barrier 102 and described silicon substrate 101 are carried out the through hole 104 that etching formation penetrates silicon, the described through hole 104 that penetrates silicon penetrates described insulating barrier 102 and enters into described silicon substrate 101.

Step 2, deposit the first laying 105, described the first laying 105 are positioned at described contact hole 103 and described sidewall and lower surface and other regional insulating barrier 102 surfaces that penetrate the through hole 104 of silicon.Described the first laying 105 is comprised of titanium and the titanium nitride of successively deposit, and the thickness of the titanium of described the first laying 105 is The thickness of the titanium nitride of described the first laying 105 is

Step 3, on described the first laying 105 deposit ground floor tungsten 106, described ground floor tungsten 106 is filled described contact hole 103 fully.The thickness of described ground floor tungsten 106 is

Step 4, described ground floor tungsten 106 is carried out the first time return to carve, return the described first time to carve and rest on described the first laying 105.

Deposit the second laying 107 on the surface of step 5, formation after returning quarter described first time.Described the second laying 107 is titanium nitride, and the thickness of described the second laying 107 is

Step 6, on described the second laying 107 deposit second layer tungsten 108; Described second layer tungsten 108 is carried out the second time return to carve, return the described second time to carve and rest on described the second laying 107.The thickness of described second layer tungsten 108 is

Step 7, repeating step six until the described through hole that penetrates silicon 104 filled up fully by tungsten.Described tungsten is described ground floor tungsten 106 and the described second layer tungsten 108 of deposit repeatedly.

Step 8, employing chemical mechanical milling tech are all removed the tungsten on described insulating barrier 102 surfaces on the described silicon substrate 101, described the first laying 105 and described the second laying 107.Behind the cmp, the surface that is filled in described contact hole 103 and the tungsten of the described through hole 104 that penetrates silicon is equal with described insulating barrier 102 surfaces.

More than by specific embodiment the present invention is had been described in detail, but these are not to be construed as limiting the invention.In the situation that does not break away from the principle of the invention, those skilled in the art also can make many distortion and improvement, and these also should be considered as protection scope of the present invention.

Claims

1. a process that penetrates the filling through hole tungsten plug of silicon is characterized in that, comprises the steps:

Step 1, the silicon substrate that provides a surface to be formed with insulating barrier adopt chemical wet etching technique that described insulating barrier etching is formed contact hole, and described contact hole is arranged in described insulating barrier and contacts with described surface of silicon; Then, adopt chemical wet etching technique that described insulating barrier and described silicon substrate are carried out the through hole that etching formation penetrates silicon, the described through hole that penetrates silicon penetrates described insulating barrier and enters into described silicon substrate;

Step 2, deposit the first laying, described the first laying are positioned at described contact hole and described sidewall and lower surface and other the regional surface of insulating layer that penetrates the through hole of silicon;

Step 3, on described the first laying deposit ground floor tungsten, described ground floor tungsten is filled described contact hole fully;

Step 4, described ground floor tungsten is carried out the first time return to carve, return the described first time to carve and rest on described the first laying;

Deposit the second laying on the surface of step 5, formation after returning quarter described first time;

Step 6, on described the second laying deposit second layer tungsten; Described second layer tungsten is carried out the second time return to carve, return the described second time to carve and rest on described the second laying;

Step 7, repeating step six until the described through hole that penetrates silicon filled up fully by tungsten;

2. penetrate as claimed in claim 1 the process of the filling through hole tungsten plug of silicon, it is characterized in that: described first laying of deposit is comprised of titanium and the titanium nitride of successively deposit in the step 2, and the thickness of the titanium of described the first laying is

The thickness of the titanium nitride of described the first laying is

3. penetrate as claimed in claim 1 the process of the filling through hole tungsten plug of silicon, it is characterized in that: the thickness of the tungsten of ground floor described in the step 3 is

4. penetrate as claimed in claim 1 the process of the filling through hole tungsten plug of silicon, it is characterized in that: the second laying described in the step 5 is titanium nitride, and the thickness of described the second laying is

5. penetrate as claimed in claim 1 the process of the filling through hole tungsten plug of silicon, it is characterized in that: the thickness of the tungsten of the second layer described in the step 6 is