KR101057360B1 - Etchant composition for single layer and multi layers consisting of aluminum or aluminum alloy or/and molybdenum or molybdenum alloy - Google Patents

Abstract

The present invention relates to a new type of etchant composition for etching single and multilayer films consisting of aluminum or aluminum alloys, and / or molybdenum or molybdenum alloys, comprising 56 to 70% by weight phosphoric acid and 2 to 2 nitric acid, based on the total weight of the total composition. An etchant composition is provided which contains 9 wt%, acetic acid 7-15 wt%, additives 0.1-5 wt% and water so that the total weight is 100 wt%. The additives here can in particular be used as potassium compounds or sodium compounds and mixtures thereof. According to the present invention, as the size of the substrate increases, the uniformity of the taper angle of the metal used for gate and data, which is difficult to control with the conventional phosphoric acid, nitric acid, and acetic acid types, can be controlled, as well as providing good etching characteristics. can do.

Description

ETCHANT COMPOSITION FOR SINGLE LAYER AND MULTI LAYERS CONSISTING OF ALUMINUM OR ALUMINUM ALLOY OR / AND MOLYBDENUM OR MOLYBDENUM ALLOY}

The present invention relates to a novel etchant composition used for wet etching of metal films in semiconductor devices, and more particularly to aluminum or aluminum alloys used in thin film transistor liquid crystal display (TFT-LCD) processes, and / or molybdenum or molybdenum The present invention relates to a new type of etchant composition for etching single and multilayer films made of alloys.

The process of forming the metal wiring on the substrate in the semiconductor device is generally composed of a metal film forming process by sputtering, a photoresist forming process in a selective region by photoresist coating, exposure and development, and an etching process. And washing processes before and after individual unit processes. The etching process refers to a process of leaving a metal film in a selective region using a photoresist mask, and typically, a dry etching using a plasma or the like, or a wet etching using an etching solution is used.

In such semiconductor devices, metals commonly used as wiring materials for TFT-LCDs are aluminum or aluminum alloys, and pure aluminum is used in the form of aluminum alloys because it is poorly resistant to chemicals and can cause wiring bonding problems in subsequent processes. Or a multi-layered laminate structure having another metal layer, such as molybdenum, chromium, tungsten, tin or the like, on top of the aluminum or aluminum alloy layer.

For example, a Mo / Al-Nd double layer can be commonly etched with a phosphate-based aluminum etchant, but molybdenum overhang occurs due to the difference in etching rates between the two layers. .

As described above, when the metal film for forming wiring of a semiconductor device such as a TFT-LCD has a multi-layer structure, it is common to compensate for the disadvantages of each other by applying a wet process and a dry process together.

When the Mo / Al-Nd bilayer is wet etched with a prior art aluminum etchant, the upper molybdenum layer protrudes out of the lower Al-Nd alloy layer because the etching rate of the upper molybdenum layer is smaller than that of the aluminum alloy layer. It indicates a poor profile having a cross section. This poor profile results in poor step coverage in the subsequent process and increases the likelihood that the top layer is disconnected from the slope or the upper and lower metals are shorted. In this case, it is common to apply a two-step process of wet etching first with an aluminum etching solution and again dry etching the upper layer which protrudes out of the lower layer due to the difference in etching rate. It is complicated and disadvantageous in terms of productivity and cost, and there are problems such as product damage.

In response to this prior art, patent application No. 1999-41119 filed by the present applicant (published number 2001-28729) discloses a phosphoric acid-main component etching solution, and specifically changes the composition ratio of phosphoric acid, nitric acid and acetic acid. This eliminates the poor profile in which the upper molybdenum layer has a cross section protruding out of the lower aluminum alloy layer and obtains an excellent profile such that no additional dry etching is required, thereby comparing the prior art of the two step process. The etching was very simple and economical.

However, as the metal film is formed of aluminum or aluminum alloy and / or molybdenum or molybdenum alloy, the film quality is varied and the size of the glass substrate is increased, so that the existing product has a uniform taper angle. There is a limit.

Accordingly, the present inventors have diligently tried to solve these problems, and as a result, by adding an additive of a potassium-based compound to a conventional aluminum etchant, that is, phosphoric acid, nitric acid, and acetic acid, an etchant having a characteristic different from the existing type could be developed. New forms of etchant are Al, Al-Nd, Mo, Mo-W, Mo / Al-Nd, Mo-W / Al-Nd, Mo / Al / Mo, Mo / Al-Nd / Mo The use of alloys and / or single and multi-layered films made of molybdenum or molybdenum alloys has the disadvantages of poor etching of upper and lower metals, poor aluminum inclination, uniformity, and increased side etching due to differences in panel and pad etching. It has been found that this can be completely solved and the present invention has been completed.

According to the present invention, in the conventional phosphate system, as the size of the panel increases, the uniformity decrease due to the difference in partial etching time of the panel, staining may occur, and the problem of poor etching of the upper or lower metals and the problem of inclination angle are all. There is an advantage that can be solved.

Finally, it is an object of the present invention to improve the uniformity which is a problem in the phosphate-based etchant while increasing the size of panels of single and multilayer films made of aluminum or aluminum alloys and / or molybdenum or molybdenum alloys used during the TFT-LCD process. It is to provide an etchant composition that solves the problem.

As a means for realizing the present invention, there is provided an etching solution composition consisting of phosphoric acid, nitric acid, acetic acid, potassium-based compound or / and sodium-based compound, water.

More specifically, 56 to 70% by weight of phosphoric acid, 2 to 9% by weight of nitric acid, 7 to 15% by weight of acetic acid, 0.1 to 5% by weight of potassium-based compound and / or sodium compound, and total weight of the total composition An etchant composition containing water to be 100% by weight is provided.

As a more preferred embodiment of the present invention, the present invention is based on 60 to 70% by weight of phosphoric acid, 4 to 7% by weight of nitric acid, 8 to 11% by weight of acetic acid, 0.1 to 2% by weight of potassium-based compounds and / or sodium-based compounds An etchant composition is provided which contains water such that the total weight of the composition is 100% by weight. Hereinafter, the present invention will be described in more detail.

The etchant composition according to the present invention is an etchant for etching single and multilayer films made of aluminum or an aluminum alloy, and / or molybdenum or molybdenum alloy.

In the present invention, a single film and a multilayer film made of aluminum or an aluminum alloy, and / or molybdenum or molybdenum alloy may have various forms. For example, in the case of Mo / Al-Nd double film, the molybdenum film is used as the upper film and Al-Nd is used. The film is used as the lower film or vice versa. In the case of the Mo-W / Al-Nd double film, the Mo-W alloy film is used as the upper film, and the Al-Nd alloy film is used as the lower film. In the case of Mo / Al / Mo and Mo / Al-Nd / Mo triple films, molybdenum films are used as the upper and lower films, and pure aluminum and Al-Nd films are used as the intermediate films. In the structure of the film, molybdenum may also be used in the form of an alloy with a metal such as tungsten. In addition, the multilayer film described above is used in the form of a single film, such as Al, Al-Nd, Mo, Mo-W.

There potassium compound used in the etchant compositions of the present invention, the kind is not particularly limited, for example, _{KC 2 H 3 O 2, K} 2 CO 3, KClO 3, KCl, KF, KHSO 4, KNO 3, K 2 C ₂ O ₄ , KClO ₄ , K ₂ O ₈ S ₂ , KH ₂ PO ₄ , K ₂ HPO ₄ , K ₃ PO ₄ and K ₂ SO ₄ , and the like, and preferably KNO ₃ , or KC ₂ H _{3 is} O ₂ . The type of sodium compound is not particularly limited, but for example, NaC ₂ H ₃ O ₂ , Na ₂ CO ₃ , NaClO ₃ , NaCl, NaF, NaHSO ₄ , NaNO ₃ , Na ₂ C ₂ O ₄ , NaClO ₄ , Na ₂ O ₈ S ₂ , NaH ₂ PO ₄ , Na ₂ HPO ₄ , Na ₃ PO ₄ , Na ₂ SO ₄ , and the like, and preferably NaC ₂ H ₃ O ₂ .

The present invention relates to a new type of etchant composition for etching single and multi-layer films made of aluminum or aluminum alloys, and / or molybdenum or molybdenum alloys, without any dependence of equipment and capable of etching various kinds of substrates. Can provide an etching solution having good etching characteristics.

Example  1 to 80

Mo / Al-Nd, Mo-W / Al-Nd bilayers and Mo / Al / Mo, Mo / Al-Nd / Mo triple layer substrates were prepared. An etching solution containing phosphoric acid, nitric acid, acetic acid, additives, and the remaining water in the composition ratios shown in Tables 1, 2, 3, and 4 was prepared to be 180 kg. Etching solution prepared in the spray etching method (KDNS Co., Ltd., model name: ETCHER (TFT)) was added to warm the temperature was set to 40 ℃, the etching process was performed when the temperature reaches 40 ± 0.5 ℃. Overetch (O / E: Over Etch) was performed at 30% and 50% based on EPD (End Point Detection) of the pad part. The substrate was inserted and sprayed, and when the etching was completed, the substrate was taken out, washed with deionized water, dried using a hot air dryer, and removed using a photoresist stripper. After washing and drying, the etching profile was evaluated by using an electron scanning microscope (SEM; manufactured by HITACHI, model name: S-4700) with an inclination angle, one-sided CD (critical dimension) loss, and etching residue. The results are shown in Table 1.

Example Board Composition (wt%) (phosphoric acid / nitric acid / acetic acid / KNO ₃ / water) Tilt Angle (°) One-sided CD loss (㎛)
evaluation 30% 50% 30% 50% One Mo / Al-Nd 70/3/10 / 0.5 / 16.5 65 60 0.4 0.6 Good 2 69/5/10/1/15 65 60 0.4 0.55 Good 3 65/4/10/2/19 60 60 0.3 0.4 Good 4 65/6/9 / 0.5 / 19.5 60 58 0.3 0.4 Good 5 60/4/9/1/26 62 60 0.4 0.55 Good 6 60/7/10/3/20 65 60 0.45 0.6 Good 7 65/9/10/1/15 40 40 0.5 0.6 Good 8 64/8/10/5/13 50 45 0.4 0.55 Good 9 Mo-W / Al-Nd 70/3/10 / 0.5 / 16.5 65 60 0.35 0.5 Good 10 69/5/10/1/15 68 65 0.4 0.5 Good 11 65/4/10/2/19 60 60 0.3 0.4 Good 12 65/6/9 / 0.5 / 19.5 60 60 0.3 0.4 Good 13 60/4/9/1/26 65 60 0.4 0.5 Good 14 60/7/10/3/20 65 60 0.4 0.55 Good 15 65/9/10/1/15 40 38 0.5 0.6 Good 16 64/8/10/5/13 50 45 0.4 0.55 Good 17 Mo / Al / Mo 70/3/10 / 0.5 / 16.5 70 72 0.35 0.5 Good 18 69/5/10/1/15 68 69 0.4 0.55 Good 19 65/4/10/2/19 70 70 0.3 0.4 Good 20 65/6/9 / 0.5 / 19.5 68 70 0.3 0.35 Good 21 60/4/9/1/26 65 66 0.4 0.55 Good 22 60/7/10/3/20 60 62 0.45 0.6 Good 23 65/9/10/1/15 50 50 0.45 0.55 Good 24 64/8/10/5/13 55 56 0.45 0.5 Good 25 Mo / Al-Nd / Mo 70/3/10 / 0.5 / 16.5 70 72 0.35 0.5 Good 26 69/5/10/1/15 68 69 0.37 0.55 Good 27 65/4/10/2/19 70 70 0.3 0.4 Good 28 65/6/9 / 0.5 / 19.5 68 70 0.3 0.35 Good 29 60/4/9/1/26 65 66 0.4 0.55 Good 30 60/7/10/3/20 62 62 0.42 0.59 Good 31 65/9/10/1/15 50 50 0.45 0.55 Good 32 64/8/10/5/13 55 55 0.45 0.5 Good

Example Board Composition (wt%) (phosphoric acid / nitric acid / acetic acid / KNO ₃ / KC ₂ H ₃ O ₂ / water) Tilt Angle (°) One-sided CD loss (㎛)
evaluation 30% 50% 30% 50% 33 Mo-W / Al-Nd 70/3/10 / 0.5 / 16.5 65 60 0.35 0.5 Good 34 69/5/10/1/15 65 65 0.4 0.45 Good 35 65/4/10/2/19 60 60 0.3 0.4 Good 36 65/6/9 / 0.5 / 19.5 60 60 0.3 0.4 Good 37 60/4/9/1/26 65 63 0.4 0.45 Good 38 60/7/10/3/20 65 60 0.4 0.5 Good 39 65/9/10/1/15 40 40 0.45 0.5 Good 40 64/8/10/5/13 50 45 0.4 0.5 Good 41 Mo / Al-Nd / Mo 70/3/10 / 0.5 / 16.5 70 70 0.35 0.5 Good 42 69/5/10/1/15 68 70 0.35 0.5 Good 43 65/4/10/2/19 70 70 0.3 0.4 Good 44 65/6/9 / 0.5 / 19.5 68 68 0.3 0.35 Good 45 60/4/9/1/26 65 68 0.4 0.55 Good 46 60/7/10/3/20 60 60 0.4 0.55 Good 47 65/9/10/1/15 50 50 0.4 0.5 Good 48 64/8/10/5/13 55 56 0.4 0.5 Good

Example Board Composition (wt%) (phosphoric acid / nitric acid / acetic acid / NaC ₂ H ₃ O ₂ / water) Tilt Angle (°) One-sided CD loss (㎛)
evaluation 30% 50% 30% 50% 49 Mo-W / Al-Nd 70/3/10 / 0.5 / 16.5 65 60 0.4 0.5 Good 50 69/5/10/1/15 65 65 0.4 0.5 Good 51 65/4/10/2/19 60 60 0.3 0.4 Good 52 65/6/9 / 0.5 / 19.5 60 60 0.3 0.4 Good 53 60/4/9/1/26 65 65 0.4 0.5 Good 54 60/7/10/3/20 65 60 0.4 0.5 Good 55 65/9/10/1/15 40 38 0.5 0.6 Good 56 64/8/10/5/13 50 45 0.4 0.55 Good 57 Mo / Al-Nd / Mo 70/3/10 / 0.5 / 16.5 70 70 0.4 0.5 Good 58 69/5/10/1/15 68 68 0.4 0.5 Good 59 65/4/10/2/19 70 70 0.3 0.4 Good 60 65/6/9 / 0.5 / 19.5 68 70 0.3 0.35 Good 61 60/4/9/1/26 65 65 0.4 0.5 Good 62 60/7/10/3/20 62 62 0.45 0.55 Good 63 65/9/10/1/15 50 50 0.45 0.55 Good 64 64/8/10/5/13 55 55 0.45 0.5 Good

Example Board Composition (wt%) (phosphoric acid / nitric acid / acetic acid / KNO ₃ / NaC ₂ H ₃ O ₂ / water) Tilt Angle (°) One-sided CD loss (㎛)
evaluation 30% 50% 30% 50% 65 Mo-W / Al-Nd 70/3/10 / 0.5 / 16.5 65 60 0.4 0.5 Good 66 69/5/10/1/15 65 65 0.4 0.45 Good 67 65/4/10/2/19 60 60 0.3 0.4 Good 68 65/6/9 / 0.5 / 19.5 60 60 0.3 0.4 Good 69 60/4/9/1/26 65 60 0.4 0.5 Good 70 60/7/10/3/20 65 60 0.4 0.5 Good 71 65/9/10/1/15 40 40 0.5 0.6 Good 72 64/8/10/5/13 50 45 0.45 0.55 Good 73 Mo / Al-Nd / Mo 70/3/10 / 0.5 / 16.5 70 70 0.35 0.5 Good 74 69/5/10/1/15 68 68 0.35 0.55 Good 75 65/4/10/2/19 70 70 0.3 0.4 Good 76 65/6/9 / 0.5 / 19.5 68 70 0.3 0.35 Good 77 60/4/9/1/26 65 65 0.4 0.5 Good 78 60/7/10/3/20 62 62 0.45 0.55 Good 79 65/9/10/1/15 50 50 0.45 0.55 Good 80 64/8/10/5/13 55 55 0.45 0.5 Good

Claims (1)

Etch solution containing 56 to 70% by weight of phosphoric acid, 2 to 9% by weight of nitric acid, 7 to 15% by weight of acetic acid, 0.1 to 5% by weight of additives, and water so that the total weight of the total composition is 100% by weight. As a composition,
The additive is NaC ₂ H ₃ O ₂ , NaClO ₃ , NaCl, NaHSO ₄ , NaNO ₃ , Na ₂ C ₂ O ₄ , NaClO ₄ , Na ₂ O ₈ S ₂ , NaH ₂ PO ₄ , Na ₂ HPO ₄ , Na ₃ An etching solution composition for etching a single film and a multilayer film made of aluminum or an aluminum alloy, and / or molybdenum or molybdenum alloy, characterized in that the sodium-based compound selected from the group consisting of PO ₄ and Na ₂ SO ₄ .