JP3065726B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a thin film transistor (TF) used for driving a liquid crystal display, electroluminescence and the like.
T). In recent years, liquid crystal displays with larger screens have been demanded, and development of their manufacturing technology has become urgent. It is also important to improve the reliability and yield as products, and one of them is the problem of cleaning the substrate surface in each process. In particular, dry etching of the metal film,
After the resist is stripped by the stripping solution, the deteriorated resist is likely to remain on the metal film pattern edges and the like.If film formation is performed in this state, abnormal growth and the like will occur in the portion where the deteriorated resist remains, and the reliability and There was a problem that the yield was reduced.

Therefore, there is a demand for a method of manufacturing a semiconductor device capable of improving the reliability and yield as a product by removing a deteriorated resist remaining on a metal film pattern edge or the like after removing the resist.

[0003]

2. Description of the Related Art A TFT manufacturing process includes a resist stripping step using an organic stripping liquid each time a pattern is formed on each layer. Conventionally, in a method of manufacturing a semiconductor device of this type, as shown in FIG. 5A, a gate metal film pattern 33 is formed on a substrate 31 by dry etching a metal film using a resist pattern 32 by RIE or the like. , FIG.
As shown in (b), the resist pattern 32 is stripped with an organic resist stripper, and isopropyl alcohol (IP) is removed.
A) After replacement, washing and drying, as shown in FIG. 5C, the gate metal film pattern 33 is formed by the P-CVD method.
An insulating film 34 such as SiO ₂ / SiN is formed so as to cover.

[0004]

In the above-described conventional method for manufacturing a semiconductor device, the resist pattern 32 is used
When the gate metal film pattern 33 is formed by dry etching of E or the like, the resist is deteriorated and remains on the edges of the gate metal film pattern 33, though it is extremely thin. Even if the resist is peeled off, it is difficult to completely remove the deteriorated resist remaining particularly on the edge of the gate metal film pattern 33 and the like.

For this reason, if a film is formed in a state where the deteriorated resist remains on the edge of the gate metal film pattern 33 or the like, abnormal growth may occur in the portion where the deteriorated resist remains, or infiltration of an etching solution or the like in a subsequent process. There has been a problem that the reliability and yield as a product are reduced, for example, the lower gate metal film pattern 33 is corroded.

Accordingly, the present invention can substantially completely remove the deteriorated resist remaining on the metal film pattern edge after the dry etching, and hardly causes abnormal growth and corrosion of the metal film pattern due to penetration of an etching solution or the like. It is an object of the present invention to provide a method of manufacturing a semiconductor device which can improve the reliability and yield as a product.

[0007]

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention comprises the steps of: forming a metal film pattern by dry etching a metal film using a resist pattern as a mask; Removing the metal film pattern with a resist stripper, then subjecting the metal film pattern to a surface treatment by sputter etching with an ion beam of an inert gas in a high vacuum, and then forming an insulating film so as to cover the metal film pattern. And forming a film.

In the present invention, the end point of the sputter etching may be controlled by monitoring the concentration of the surface element by XPS and based on the monitored concentration value of the predetermined element. May be controlled by monitoring the amount of secondary ions or backscattered ions generated at the time of collision of inert gas ions, and based on the monitored predetermined amount of ions.

[0009]

According to the present invention, as shown in FIG. 1, the metal film pattern 2 is subjected to a surface treatment by sputter etching using an Ar gas ion beam in a high vacuum before the film formation after the resist is stripped. The deteriorated resist remaining on the edge of the film pattern 2 can be almost completely removed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 and 2 are views for explaining a method of manufacturing a semiconductor device according to one embodiment of the present invention. The illustrated example is a case where the method is applied to a method of manufacturing an inverted staggered TFT. 1 and 2, 1
Is a transparent insulating substrate such as glass, and a metal film pattern 2 serving as a gate such as an Al film / Ti film is formed on the transparent insulating substrate 1. Reference numeral 3 denotes a resist pattern serving as an etching mask when forming the metal film pattern 2. Reference numerals 4, 5, and 6 denote gate insulating films such as a SiO ₂ film / SiN film, operating semiconductor films such as α-Si, and SiN and the like. It is a protective layer. Reference numeral 7 denotes a contact layer made of n ⁺ α-Si or the like, on which a source / drain electrode 8 made of Ti or the like is formed. Reference numeral 9 denotes a drain bus such as Al for connecting a drain, and reference numeral 10 denotes a pixel electrode such as ITO formed to be connected to the source electrode.

Next, a method of manufacturing the semiconductor device will be described. First, as shown in FIG. 1A, a metal film composed of an Al film / Ti film is
A metal film pattern 2 serving as a gate electrode, a gate bus line, and a gate terminal is formed on the transparent insulating substrate 1 by dry etching with E or the like.

Next, as shown in FIG. 1B, the resist pattern 3 used as an etching mask is removed with an organic resist stripper such as N-methyl-2-pyrrolidone. Next, the surface of the metal film pattern 2 is subjected to sputter etching using an ion beam of an inert gas such as Ar in a high vacuum of about 10 ⁻⁶ Torr. Sputter etching here monitors the Ti concentration of the surface element constituting the metal film pattern 2 by XPS in a P-CVD apparatus as shown in FIG. 3, and when the monitored Ti concentration of the predetermined element exceeds a certain level. Terminate.

Next, as shown in FIG. 1C, a gate insulating film 4 composed of a SiO ₂ film / SiN film, an active semiconductor film 5 composed of α-Si, and S
A protective layer 6 made of iN is continuously formed. Next, FIG.
As shown in (d), the SiN protective layer 6 is
Wet etching is performed so that the upper region remains.

Next, as shown in FIG. 2E, a contact layer 7 made of n ⁺ α-Si is formed so as to cover the SiN protective layer.
And a source / drain electrode 8 made of Ti.
After performing element isolation, forming an Al drain bus 9 for connecting a drain, forming an ITO pixel electrode 10 so as to connect to a source electrode, etching the gate insulating film 4 to obtain a gate terminal. FIG. 2
A semiconductor device as shown in (f) can be obtained.

As described above, in the present embodiment, the metal film pattern 2 is subjected to the surface treatment by sputter etching using an Ar gas ion beam in a high vacuum before the film formation after the resist is stripped. The deteriorated resist remaining on the two edges can be almost completely removed. For this reason, corrosion or the like of the metal film pattern 2 due to abnormal growth and permeation of an etchant or the like, which have conventionally occurred, can be made difficult to occur. Therefore, the reliability and yield as a product can be improved. The removal of the deteriorated resist remaining on the edge of the metal film pattern 2 could be confirmed by observation with a TEM or the like.

In the above embodiment, the sputter etching is monitored by XPS to monitor the Ti concentration of the surface element constituting the metal film pattern 2, and when the monitored Ti concentration of the predetermined element exceeds a certain level, the etching is terminated. In the preferred embodiment which can be performed without increasing the number of steps, the present invention is not limited to this, and as shown in FIG. It is also possible to monitor the C amount of secondary ions (or backscattered ions) generated at the time of collision and terminate the process when the monitored predetermined C amount falls below a certain level to perform in-line.

[0017]

According to the present invention, the deteriorated resist remaining on the edge of the metal film pattern after dry etching can be almost completely removed, and abnormal growth and corrosion of the metal film pattern due to penetration of an etching solution or the like can be achieved. Is less likely to occur, and there is an effect that the reliability and yield as a product can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for manufacturing a semiconductor device according to one embodiment of the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing a semiconductor device according to one embodiment of the present invention.

FIG. 3 is a diagram showing a monitoring result by XPS during sputter etching according to one embodiment of the present invention.

FIG. 4 is a diagram showing a result of monitoring secondary ions during sputter etching applicable to the present invention.

FIG. 5 is a diagram illustrating a method of manufacturing a conventional semiconductor device.

[Explanation of symbols]

 2 Metal film pattern 3 Resist pattern 4 Gate insulating film

(56) References JP-A-58-56336 (JP, A) JP-A-4-261018 (JP, A) JP-A-5-13394 (JP, A) (58) Fields studied (Int) .Cl. ⁷ , DB name) H01L 21/3065 G02F 1/1343

Claims (3)

(57) [Claims] A step of dry-etching the metal film using the resist pattern as a mask to form a metal film pattern; and a step of removing the resist pattern with a resist stripper. Next, a step of subjecting the metal film pattern (2) to surface treatment by sputter etching using an ion beam of an inert gas in a high vacuum, and then forming an insulating film (4) so as to cover the metal film pattern (2). Forming a film. 2. The method according to claim 1, wherein the end point of said sputter etching is XPS
2. The method according to claim 1, wherein the surface element concentration is monitored by (X-ray photoelectron spectroscopy), and the surface element concentration is controlled based on the monitored concentration value of the predetermined element. 3. The end point of the sputter etching is monitored based on the amount of secondary ions or backscattered ions generated at the time of collision of inert gas ions and based on the monitored amount of ions of a predetermined element. The method for manufacturing a semiconductor device according to claim 1, wherein: