A method for preparing a film layer suitable for TFT LCD display devices

Abstract

This invention discloses a method for preparing a film layer suitable for TFT LCD display devices, including Island Layer preparation and SD Layer preparation. It utilizes two masks with different photolithography amounts to achieve varying exposure levels for different patterns, thus fulfilling the requirements for different photoresist exposures. Compared to existing technologies, this invention proposes reducing the number of processes by using two ordinary masks, equivalent to Halftone masks. The two film layers are completed in a single photolithography process, i.e., one coating, two exposures, and one development process. Compared to existing technologies, this invention controls the photolithography amount through process control. Different photolithography amounts on the two masks result in different exposure levels for different patterns, fulfilling the requirements for different photoresist exposures, i.e., achieving fully exposed, partially exposed, and unexposed patterns, equivalent to the Halftone technology effect. However, the manufacturing process is relatively simpler and more mature, with lower costs, shorter lead times, and better film quality.

Description

Technical Field

[0001] This invention belongs to the field of TFT LCD display devices, and specifically relates to a method for preparing a film layer suitable for TFT LCD display devices. Background Technology

[0002] As TFT LCD display devices become more and more popular, the market demand for this product is also increasing. In order to reduce costs, improve yield, and shorten the production cycle, the improvement of TFT manufacturing process has never stopped.

[0003] In TFT LCD display devices, film layers refer to the thin films that cover or coat different levels of the display panel. These films are typically formed on the display panel through specific process steps and have different functions and properties.

[0004] Among the existing film layers are the Island Layer (silicon island layer) and the SD Layer (source / drain layer).

[0005] Island Layer (Silicon Island Layer): A silicon island layer typically consists of intrinsic amorphous silicon (Ia-Si) and n+ ion-doped amorphous silicon (n+ ion-doped silicon). + It is composed of (a-Si). Ia-Si can form the conductive channel between the source and drain. And n + An ohm contact structure is formed between the a-Si and the source / drain electrodes. The ohm contact structure is the transition region between the TFT device and the external signal line.

[0006] SD Layer (Source-Drain Layer): S stands for source, and D stands for drain. SD refers to the source and drain layers. In TFT liquid crystal displays, the source and drain layers refer to the source and drain regions in the thin-film transistor (TFT) structure. In a TFT liquid crystal display, when an appropriate voltage signal is applied to the gate, the current path between the source and drain is opened, allowing current to flow. The distribution pattern of this current is called the SD pattern (source-drain pattern). Non-uniform distribution of the SD pattern can lead to uneven brightness or color of the image on the display.

[0007] To achieve a more uniform SD pattern distribution, the design and process of the source and drain layers need to be optimized during the manufacturing of TFT liquid crystal displays. This includes controlling the shape, size, and material properties of the source and drain regions, as well as reducing issues such as resistance, current leakage, and uneven current distribution between the source and drain.

[0008] These two film layers play an important role in the TFT LCD manufacturing process, ensuring the reliability of signal transmission and circuit structure.

[0009] like Figure 2 As shown, the existing Half Tone special process can produce two film layers by creating three different transmittances on a single mask, saving one mask, reducing the manufacturing process, and increasing productivity.

[0010] While the Half Tone process offers some advantages in TFT LCD display manufacturing, it also has some drawbacks, including:

[0011] 1. High Production Difficulty: Compared to traditional methods, the Half Tone process requires creating multiple different light transmission modes on a single mask, necessitating specialized techniques and equipment. Therefore, mastering and implementing this complex process may require additional technical expertise and knowledge for manufacturers.

[0012] 2. Higher Cost: The Half Tone process is relatively complex, requiring manufacturers to invest more resources and costs. Especially in mask manufacturing, specialized technologies and equipment are needed to achieve different levels of light transmittance, which may lead to additional manufacturing and equipment investments.

[0013] 3. Longer cycle time: Compared to traditional manufacturing processes, the Half Tone process is potentially more complex and time-consuming, leading to a longer manufacturing cycle. This can impact a manufacturer's production plans and delivery times.

[0014] 4. High Requirements for Process Parameter Control: The successful implementation of the Half Tone process requires precise control of process parameters, including accurate control and stability of light transmittance. During the manufacturing process, variations in process parameters must be strictly controlled to ensure that the manufactured product meets design requirements and standards.

[0015] In summary, the existing Half Tone still has many problems, such as high manufacturing difficulty, high cost, long cycle time, and relatively complex process. Summary of the Invention

[0016] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method that is easy to manufacture and has a simple process.

[0017] To solve the above-mentioned technical problems, the technical method adopted by the present invention is as follows: The present invention discloses a film layer preparation method suitable for TFTLCD display devices, including Island Layer preparation and SD Layer preparation, using two masks, and using different photolithography amounts in the process to give different patterns different exposures, thereby meeting the requirements of different exposures of photoresist.

[0018] Furthermore, the two masks are Mask1 and Mask2, respectively;

[0019] The Mask1 includes a zero-transmittance area and a fully transparent area;

[0020] The Mask2 includes a zero-transmittance area and a non-fully transparent area.

[0021] Furthermore, the transmittance of the non-fully transparent area of ​​the Mask2 is 30%-60%.

[0022] Furthermore, Mask1 is selected in the fabrication of the SD Layer.

[0023] Furthermore, the fabrication of the SD Layer includes the following steps:

[0024] SA1. SD Pattern, a line pattern formed on the SD Layer;

[0025] SA2. Prepare Mask1 that matches the SD Pattern;

[0026] SA3. The pattern on the mask is projected onto the photosensitive material using a light source;

[0027] SA4. After exposure, the photosensitive material is treated with a specific developer to remove the unexposed material, leaving the area where chemical or physical changes occur after exposure, thus obtaining the desired SD Pattern on the SD Layer.

[0028] Furthermore, Mask2 is selected in the preparation of the Island Layer.

[0029] Furthermore, the preparation of the Island Layer includes the following steps:

[0030] SB1. Island Pattern, a line pattern formed on the Island Layer;

[0031] SB2. Prepare a Mask2 that matches the Island Pattern;

[0032] SB3. The pattern on the mask is projected onto the photosensitive material using a light source;

[0033] SB4. After exposure, the photosensitive material is treated with a specific developer to remove the unexposed material, leaving the area where chemical or physical changes occur after exposure, thus obtaining the desired SD Pattern on the SD Layer.

[0034] Furthermore, the SD Layer is a metal conductor layer, and the Island Layer is an active semiconductor layer.

[0035] Furthermore, the material used in the Island Pattern includes amorphous silicon.

[0036] Furthermore, the SD Pattern is made using molybdenum-aluminum material.

[0037] Beneficial effects:

[0038] Compared to existing technologies, this invention proposes to reduce the manufacturing process by using two ordinary masks equivalent to Halftone Masks. This allows the two film layers to be completed in a single photolithography process, namely, one coating, two exposures, and one development process. Compared to existing technologies, this invention controls the amount of photolithography through process control. The two masks use different amounts of photolithography to achieve different exposure levels for different patterns, thus meeting the different exposure requirements of photoresist, i.e., achieving fully exposed, partially exposed, and unexposed patterns, equivalent to the effect of Halftone technology. However, the manufacturing process is relatively simpler and more mature, with lower costs, shorter lead times, and better quality film layers. Attached Figure Description

[0039] Figure 1 This is a process diagram showing the fabrication of the SD Layer and Island Layer using Mask1 and Mask2, respectively, in this invention.

[0040] Figure 2 This is a diagram of the existing Half Tone manufacturing process. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0042] like Figure 1 As shown, this invention discloses a method for fabricating a film layer suitable for TFT LCD display devices, including Island Layer fabrication and SD Layer fabrication. Two masks are used, and different photolithography amounts are employed to achieve different exposure levels for different patterns, thus meeting the requirements for varying photoresist exposure. The two masks are designated Mask1 and Mask2; Mask1 includes a zero-transmittance region and a fully transparent region; Mask2 includes a zero-transmittance region and a non-fully transparent region. The transmittance of the non-fully transparent region is 30%-60%.

[0043] In the preparation of the SD layer, Mask1 is selected, and the following steps are included:

[0044] SA1. SD Pattern, a line pattern formed on the SD Layer;

[0045] SA2. Prepare Mask1 that matches the SD pattern;

[0046] SA3. The pattern on the mask is projected onto the photosensitive material using a light source;

[0047] SA4. After exposure, the photosensitive material is treated with a specific developer to remove the unexposed material, leaving the areas that have undergone chemical or physical changes after exposure, thus obtaining the desired SD pattern on the SD layer.

[0048] In the preparation of the Island Layer, Mask2 is selected, and the following steps are included:

[0049] SB1. Island Pattern, a line pattern formed on the Island Layer;

[0050] SB2. Prepare Mask2 that matches the Island Pattern;

[0051] SB3. The pattern on the mask is projected onto the photosensitive material using a light source;

[0052] SB4. After exposure, the photosensitive material is treated with a specific developer to remove the unexposed material, leaving the areas that have undergone chemical or physical changes after exposure, thus obtaining the desired SD pattern on the SD layer.

[0053] In this embodiment, the Island Pattern is made of amorphous silicon; the SD Pattern is made of molybdenum-aluminum material.

[0054] like Figure 2 As shown, this patent proposes to reduce the number of processes by using two ordinary masks equivalent to Halftone Masks, so that the two film layers (Island Layer and SD Layer) can be completed in only one photolithography process, namely one coating, two exposures, and one development process. The photolithography amount is controlled by the process, and the two masks use different photolithography amounts to give different patterns different exposures, so as to meet the requirements of different exposures of photoresist, that is, to achieve fully exposed patterns, half-exposed patterns, and unexposed patterns, which is equivalent to the effect of Halftone technology.

[0055] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a film layer suitable for a TFT LCD display device, comprising Island Layer preparation and SD Layer preparation, characterized in that: The Island Layer and the SD Layer are fabricated through a single photolithography process, which includes one coating, two exposures, and one development. Use two Masks, Mask1 and Mask2; The Mask1 includes a zero-transmittance area and a fully transparent area; The Mask2 includes a zero-transmittance area and a non-fully transparent area; the transmittance of the non-fully transparent area of ​​the Mask2 is 30%-60%; In the fabrication of the SD Layer, Mask1 is selected, and Mask1 matches the line pattern SDPattern formed on the SD Layer; In the preparation of the Island Layer, Mask2 is selected, and the Mask2 is matched to the line pattern Island Pattern formed on the Island Layer; Different light accumulation amounts are used in the process to give different patterns different exposure levels, achieving fully exposed patterns, half-exposed patterns, and unexposed patterns.

2. The method for preparing a film layer suitable for a TFT LCD display device according to claim 1, characterized in that: The SD Layer fabrication process includes the following steps: SA1. SD Pattern, a line pattern formed on the SD Layer; SA2. Prepare Mask1 that matches the SD Pattern; SA3. The pattern on the mask is projected onto the photosensitive material using a light source; SA4. After exposure, the photosensitive material is treated with a specific developer to remove the unexposed material, leaving the area where chemical or physical changes occur after exposure, thus obtaining the desired SD Pattern on the SD Layer.

3. The method for preparing a film layer suitable for a TFT LCD display device according to claim 1, characterized in that: The preparation of the Island Layer includes the following steps: SB1. Island Pattern, a line pattern formed on the Island Layer; SB2. Prepare a Mask2 that matches the Island Pattern; SB3. The pattern on the mask is projected onto the photosensitive material using a light source; SB4. After exposure, the photosensitive material is treated with a specific developer to remove the unexposed material, leaving the area where chemical or physical changes occur after exposure, thus obtaining the desired Island Pattern on the Island Layer.

4. The method for preparing a film layer suitable for a TFT LCD display device according to claim 3, characterized in that: The SD Layer is a metal conductor layer, and the Island Layer is an active semiconductor layer.

5. The method for preparing a film layer suitable for a TFT LCD display device according to claim 3, characterized in that: The materials used in the Island Pattern include amorphous silicon.

6. The method for preparing a film layer suitable for a TFT LCD display device according to claim 2, characterized in that: The SD Pattern is made of molybdenum-aluminum material.

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