End point detecting method of metal etching and device thereof

Disclosed is an end point detecting method of metal etching and a device thereof. The end point detecting method of metal etching comprises: performing scan to a metal film to acquire a proportion of a transparency area of the metal film in a scanned area; judging whether the proportion of the transparency area reaches a predetermined value or not; and confirming a current etching time of the metal film as an etching end point time when the predetermined value is reached. The device comprises an acquirement module, a judgment module and a confirmation module. The acquirement module performs scan to the metal film to acquire the proportion of the transparency area. The judgment module judges whether the proportion reaches the predetermined value or not. The confirmation module confirms the current etching time of the metal film as the etching end point time when the proportion reaches the predetermined value.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an end point detecting method of metal etching and device thereof, and more particularly to an end point detecting method of metal etching and device thereof, capable of eliminating the effect of the set up location for the scanner of the end point detecting device of metal etching and judging the etching end point time of the metal film more precisely.

2. Description of Prior Art

Please refer toFIG. 1, which shows a diagram of that a substrate100carrying a metal film is conveyed in a metal wet etching machine10when a LCD (Liquid Crystal Display) panel is manufactured. In the LCD panel manufacture, the metal wet etching machine1is used for executing a wet etching to the metal film. The metal wet etching is to load the substrate100which the surface is plated with the metal film (metal layer) in an etching bath full of acid solution. Then, etching is performed to the area unprotected by the photoresist to obtain the patterns protected by the photoresist. Before the metal wet etching machine10is used to perform etching to a batch of metal films. One of the batch of the metal films is selected as being a sample metal film and to acquire an etching end time of the sample metal film. Two ways of performing the etching end time detection exist in the industry nowadays. One is shown inFIG. 2, which shows a diagram of that a work150executes a random check for judging the etching end time of the metal films with unaided eye by experience according to prior art. However, this way is less precise because digitized management is unable to realize. The other is to acquire the etching end time of the sample metal film through the scanner104of the EPD (End Point Detector). The etching end time is defined as the period of time from loading the substrate100into the etching bath full of acid solution till the sensor of the end point detector detects the metal film penetrated by the light (the substrate100is used for carrying the metal film).

The working theory of the end point detector is based on the light reflection/penetration. As the metal film remains on the substrate100, the light generated by the sensor of the end point detector is still reflected by the metal film because the light cannot penetrate the metal film. The end point detector judges that the end point time of the metal film has not arrived hereby; as the metal film carried by the substrate100is completely etched, the light generated by the sensor of the end point detector can penetrate the substrate100and is not be reflected because the light can penetrate the substrate100. The end point detector judges that the end point time of the metal film has arrived hereby.

However, as shown inFIG. 3, considering the functions of the metal film on the substrate100, functioning area100aand dummy area100bcan be illustrated. The dummy areas100bare the areas without patterns (without photoresist), and the patterns of the functioning areas100aare divided into a great many tiny and irregular shaped areas when the exposure process is performed. Therefore, when the functioning areas100aare etched with acid solution, the etching time is simply related with the thickness of the metal film; but the dummy areas100bhave no patterns and the entire area is relatively larger than the functioning areas100a, when the dummy areas100bare etched with acid solution, the etching happens from the exterior to the interior slower. The dummy areas100bhave the same thickness as the functioning areas100ado but the needed etching time takes longer.

Although, the etching end time of each metal film can be detected with the way through the end point detector, the set up location for the scanner104affects the judgment of end point time directly because the end point detector according to prior art as shown inFIG. 4utilizes a single point scanning manner. Generally, the set up location of the scanner104is a fixed position as performing scan. However, the distributions of the functioning areas100aand the dummy areas100bare different in the metal films of different substrates. If the fixed position of the scanner104makes the scan covers the dummy areas100bmost, it results in that the detected end point time can be longer than the really needed etching point time. Then, the error of the judgment of the end point time obviously becomes larger.

Consequently, there is a need to provide an end point detecting method of metal etching and device thereof for solving the existing drawbacks of aforementioned prior art.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide an end point detecting method of metal etching and device thereof, capable of eliminating the effect of the set up location for the scanner of the end point detecting device of metal etching and judging the etching end point time of the metal film more precisely.

For realizing the aforesaid objective of the present invention, the present invention provides an end point detecting method of metal etching, utilized with an end point detecting device of metal etching. The end point detecting method of metal etching of the present invention comprises steps below: performing scan to a metal film with a scanner to acquire a proportion of a transparency area of the metal film in a scanned area; judging whether the proportion of the transparency area of the metal film in the scanned area reaches a predetermined value or not, and if the predetermined value is not reached, then executing the step of performing scan to the metal film again after a preset latency; confirming a current etching time of the metal film as an etching end point time when the predetermined value is reached, wherein the length of the scanner is larger than or equal to the width of a substrate carrying the metal film.

In one embodiment of end point detecting method of metal etching of the present invention, the end point detecting device comprises a scanner to perform scan to the metal film, and the scanner is positioned with the direction of the length perpendicular to a conveying direction of a substrate carrying the metal film to make the scanned area obtained by the scanner cross the width of the substrate.

In one embodiment of end point detecting method of metal etching of the present invention, the area of the scanner is equal to the area of the substrate carrying the metal film.

In one embodiment of end point detecting method of metal etching of the present invention, the predetermined value of the proportion is 50%-75%.

For realizing the aforesaid objective of the present invention, the present invention provides an end point detecting method of metal etching, comprising: an acquirement module, performing scan to a metal film to acquire a proportion of a transparency area of the metal film in a scanned area; a judgment module, judging whether the proportion of the transparency area of the metal film in the scanned area reaches a predetermined value or not; and a confirmation module, confirming a current etching time of the metal film as an etching end point time when the judgment module judges that the proportion of the transparency area of the metal film in the scanned area reaches the predetermined value.

In one embodiment of end point detecting method of metal etching of the present invention, if the judgment module judges that the proportion of the transparency area of the metal film in the scanned area does not reach the predetermined value, the acquirement module is triggered to perform scan to the metal film.

In one embodiment of end point detecting method of metal etching of the present invention, the acquirement module further comprises: a scanner, performing scan to the metal film to obtain the transparency area of the metal film; and a proportion acquiring unit, acquiring the proportion of the transparency area of the metal film in the scanned area.

In one embodiment of end point detecting method of metal etching of the present invention, the length of the scanner is larger than or equal to the width of a substrate carrying the metal film to make the scanned area obtained by the scanner cross the width of the substrate.

In one embodiment of end point detecting method of metal etching of the present invention, the predetermined value of the proportion is 50%-75%.

According to the end point detecting method of metal etching and the device thereof, the effect of the set up location for the scanner of the end point detecting device of metal etching can be eliminated to judging the etching end point time of the metal film more precisely, accordingly, to promote the yield of the LCD panel manufacture.

DETAILED DESCRIPTION OF THE INVENTION

Detail descriptions of the specific embodiments of the adjustment method of the LCD overdrive voltage and the device thereof provided by the present invention in conjunction with the attached figures are introduced below.

Please refer toFIG. 3,FIG. 5,FIG. 6andFIG. 7.FIG. 5shows a block diagram of an end point detecting device of metal etching according to the present invention.FIG. 6shows a diagram of that an end point detecting device of metal etching according to the present invention is utilized for judging the etching end time of the metal film.FIG. 7shows a flowchart of an end point detecting method of metal etching according to the present invention. As shown inFIG. 5, the end point detecting device of the present invention comprises an acquirement module20, a judgment module30and a confirmation module40. The acquirement module is utilized to perform scan to a metal film to acquire a proportion of a transparency area of the metal film in a scanned area; the judgment module30is utilized to judge whether the proportion of the transparency area of the metal film in the scanned area reaches a predetermined value or not; and the confirmation module40is utilized to confirm a current etching time of the metal film as an etching end point time when the predetermined value is reached.

As shown inFIG. 6, in this embodiment of the present invention, the end point detecting controller202can be a specific embodiment of the judgment module30and the confirmation module40but not limited thereto. The acquirement module20can comprise the scanner204and the proportion acquiring unit204-1shown inFIG. 5as being the specific embodiment but not limited thereto.

In this embodiment of the present invention, the scanner204is utilized to perform scan to the metal film to obtain the transparency area of the metal film. The proportion acquiring unit204-1is utilized to acquire the proportion of the transparency area of the metal film in the scanned area. The scanner204can be optical scanner as illustration and the spectrum range and the specification can be determined according to the material of the metal film. The proportion acquiring unit204-1can be an ASIC as illustration; or the scanner204, the judgment module30and the confirmation module40are combined as an integral detection apparatus; alternatively, the portion of the proportion acquiring unit204-1, the judgment module30and the confirmation module40can be realized by hardware circuits or respective functions thereof can be realized by software programs but not limited thereto.

Furthermore, the scanner204in the acquirement module20of the end point detecting device of metal etching according to the present invention can be an individual detecting element. The proportion acquiring unit204-1, the judgment module30and the confirmation module40can be specifically realized by the interior control mechanism of the metal wet etching machine. Alternatively, all of the acquirement module20, the judgment module30and the confirmation module40in the present invention can be specifically realized by the interior control mechanism of the metal wet etching machine.

In this embodiment of the present invention, the scanner204can be located inside the metal wet etching machine to perform scan to the metal films carried by the substrates100-1or100-2. The working theory of the scanner204is introduced below: the light generated by the scanner204is emitted onto the metal films of the substrates100-1or100-2to perform scan to the metal films. Meanwhile, the scanner204further comprises a receptor (not shown) to detect whether the emitted light is reflected by the metal films of the substrates100-1or100-2. The scanner204obtains the reflection values by the receptor and transforms the reflection values into signals to be acquired by the proportion acquiring unit204-1via a DAC.

After that, the end point detecting controller202receives the signals from the proportion acquiring unit204-1to judge whether the proportion of the transparency area of the metal film in the scanned area reaches a predetermined value or not. The end point detecting controller202in this embodiment can calculate the proportion of the transparency area of the metal film of the substrates100-1or100-2in the scanned area in real time. When the predetermined value is reached, the current etching time of the metal film can be confirmed as an etching end point time. In another word, the period of time from loading the substrate with metal film into the metal wet etching machine till the current etching time is the end point time. According to the experiment results of the inventors, the predetermined value of the proportion is preferably 50%˜75%.

Furthermore, as shown inFIG. 6, in this embodiment of the present invention, the scanner204can have a rod-like appearance. The scanner204can be positioned with the direction of the length perpendicular to a conveying direction of the substrates100-1or100-2carrying the metal film. Namely, the scanner204is transversely positioned relative to the conveying direction of the substrates100-1or100-2in the metal wet etching machine. Moreover, the length of the scanner204can be larger than or equal to the width of the substrate. Thus, the scanned area obtained by the scanner204can cross the width of the substrate100-1or100-2for completely scanning the metal film thickness of the substrate100-1or100-2. Therefore, either of the functioning area100aor the dummy area100bshown inFIG. 3can be covered within the scanned area obtained by the scanner204. That is, the scanning area of the scanner204can cover the entire area of the metal film and perform scan to confirm the etched status of the entire metal film area in real time. Because the scanned area obtained by the scanner204covers the functioning area100aand the dummy area100bof the metal film, unlike prior art, because the scanned area of the scanner104according to covers the dummy areas100bmore, the more obvious error to the judgment of the of end point time happens when the judgment of the end point time is performed.

In the embodiment of the present invention, as considering the 7.5 generation LCD panel manufacture, the optimal cut size of the substrate is 2250 mm×1950 mm. Therefore, the length of the scanner204is preferably larger than 1950 mm; as considering the 8.5 generation LCD panel manufacture, the optimal cut size of the substrate is 2500 mm×2200 mm. Therefore, the length of the scanner204is preferably larger than 2200 mm. Meanwhile, if the inner space is enough and the conditions are possible, the area of the scanner204even can be equal to the entire substrate. Then, the scanner204can be set up over the substrate but not limited thereto. As long as the real performed scan can allow the etched status of the metal film to be confirmed.

Please refer toFIG. 6andFIG. 7. The end point detecting method of metal etching of the present invention can be utilized with the end point detecting device shown inFIG. 6comprising the end point detecting controller202and the scanner204to precisely judge the end point time for each of metal films.

In the embodiment of the present invention, the end point detecting method of metal etching of the present invention comprises steps below:Step701: performing scan to the metal film to acquire a proportion of a transparency area of the metal film in a scanned area;Step702: judging whether the proportion of the transparency area of the metal film in the scanned area reaches a predetermined value or not, and if the predetermined value is not reached, then returning to Step701to executing the step of performing scan to the metal film again after a preset latency, and if the proportion of the transparency area reaches the predetermined value, then proceeding the next step, Step703; and

Step703: confirming a current etching time of the metal film as an etching end point time.

In conclusion, the present invention is capable of eliminating the effect of the set up location for the scanner of the end point detecting device of metal etching and judging the etching end point time of the metal film more precisely. Accordingly, the yield of the LCD panel manufacture can be improved further.