KR19990043850A - Field Emitter Array Formation Using Mold Transfer Technology - Google Patents

Abstract

The present invention relates to a method of forming a field emitter array using a mold transfer technique, wherein a phenomenon in which silicon melts into an Al metal when heat-treating Al metal deposited on a silicon substrate is applied to an FEA manufacturing process using a mold-transfer technique. By applying it, it is possible to easily form the tip without a mask, thereby reducing the cost, and at the same time, it is possible to adjust the shape of the tip according to the heat treatment temperature, it is possible to enable the manufacturing of a large area FEA.

Description

Field Emitter Array Formation Using Mold Transfer Technology

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a field emitter array (hereinafter referred to as FEA) using mold-transfer technology. In particular, when an Al metal deposited on a silicon substrate is heat-treated, the silicon is Al. The method of forming the FEA using the mold transfer technology, which enables the formation of the tip without a mask and enables the manufacturing of a large area of the FEA by applying the melting into the metal to the FEA manufacturing process using the mold-transfer technology. It is about.

In general, a field emitter display (FED) uses a phenomenon in which an electric field is concentrated on a sharp part of a tip, and thus a relatively low voltage, for example, a voltage of about 5 to 10V, is applied by a tunnel effect. As a device for emitting cold electrons, an FED formed using the same has attracted attention as a next-generation display device because it has both the high definition of CRT and the light and thin type of liquid crystal display (hereinafter referred to as LCD).

In particular, the FED can not only manufacture the thin and thin, but also solve the problems of process yield, manufacturing cost, and enlargement, which are crucial disadvantages of the LCD.

That is, in case of LCD, even if one unit pixel is defective, the whole product is treated badly. However, FED has a smaller number of unit pixels in one pixel group, so even if one or two unit pixels are defective, There is no problem in operation, and the yield of the whole product is improved.

In addition, FED has advantages such as simple structure, low power consumption, low unit cost, and suitable for portable display device.

Initially, the FED is exposed to the outside by a cavity, and is composed of a conical cathode having a sharp part, a gate arranged on both sides of the cathode, and an anode spaced apart from the gate, each of which is a cathode and a caterpillar of the CRT. And an anode.

In the FED, a voltage is applied to the anode, for example, a voltage of about 500 to 10 mA, and electrons are emitted by an electric field concentrated at the top of the cathode, and the emitted electrons are emitted by an anode to which a positive voltage is applied. The phosphor is guided to emit the fluorescent material applied to the anode, and the gate controls the direction and amount of electrons.

However, in the early FED having the conical cathode as described above, some of the emitted electrons are induced to the gate, so that the gate current flows to control the electrons, and cations formed by colliding with the electrons between the cathode and the anode, Since the device is destroyed by collision, it is difficult to maintain the inside of the device in a high vacuum state in order to prevent this.

In addition, it is not only difficult to make a uniform conical cathode when manufacturing FEA, but also the durability is weak, which may easily damage the tip of the tip, and cross-talk between pixels due to the spreading of the emitted electron beam. There is a problem such as this occurs.

On the other hand, when the Al metal deposited on the silicon is heat-treated, the silicon melts into the Al metal. Such a phenomenon causes a fatal defect in manufacturing a MOS device. Therefore, in order to prevent the above phenomenon, about 1% silicon is added to the Al target in the MOS process.

1 is a cross-sectional view showing a spike 5 formation state for tip formation on a silicon substrate 1 according to a conventional method.

As shown in the figure, in order to form the tip forming grooves 5 on the silicon substrate 1, an oxide mask 3 must be used in a separate mask illustrated example, which makes the process of forming the mask complicated. There is a problem.

On the other hand, the phenomenon that the silicon melt into the Al metal by heat treatment is a factor that is a defect in the manufacturing of the MOS device, it can be very useful when applied to the emitter tip manufacturing of the field emission device.

Therefore, the present invention is to form a FEA having a more efficient process and useful properties in view of the above matters, an object of the present invention is that the silicon melts into the Al metal when heat-treating the Al metal deposited on the silicon substrate The present invention provides a method for forming an FEA using a mold transfer technology by easily forming a tip without a mask by applying an entering phenomenon to an FEA manufacturing process using a mold-transfer technology, thereby enabling cost reduction and large area FEA manufacturing.

1 is a cross-sectional view showing a spike formation state for forming a tip on a silicon substrate according to a conventional method.

2A-2G are cross-sectional views illustrating fabrication process steps for forming a metal field emitter array with crater shaped focusing electrodes in accordance with the techniques of the present invention.

<Explanation of symbols for main parts of drawing>

11 silicon substrate 13 Al metal

15: spike (groove) 17: thermal oxide film

19: cathode metal 21: gate metal

23: photosensitive film 25: tip

FEA forming method using the mold transfer technology of the present invention for achieving the above object,

Depositing Al metal on the silicon substrate;

Heat-treating the deposited Al metal to form spikes on a silicon substrate;

After removing the deposited Al metal, forming a thermal oxide film on the exposed silicon surface;

Depositing a cathode metal to a predetermined thickness on the entire structure;

Rotating the entire structure by 180 ° to remove the upper silicon mold;

Depositing a gate metal over the entire structure,

Applying a photoresist film to the upper portion of the structure and ashing to expose only the metal on the tip;

Sequentially etching the gate metal and the gate oxide film using the photosensitive film as a mask;

And removing the remaining photoresist to expose the tip.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the FEA manufacturing using the mold transfer technology according to the present invention.

2A-2H are cross-sectional views illustrating FEA manufacturing process steps using mold transfer technology in accordance with the method of the present invention.

First, Al metal 13 is deposited on the silicon substrate 11 (see FIG. 2A).

Next, the deposited Al metal 13 is heat-treated. At this time, during the heat treatment process, the metal is melted into the Si Al metal 13. In this case, the spike 15 is formed on the silicon substrate 11, and the Al metal 13 is filled into the spike 15.

At this time, the width of the spike 15 formed on the silicon substrate 11 is set to 1.0 to 1.5 mu m (see Fig. 2b).

After removing the deposited Al metal 13, the exposed silicon surface is thermally oxidized (see FIG. 2C).

Next, a cathode metal 19 is deposited on the entire structure to a predetermined thickness. (See FIG. 2D)

The entire structure is rotated 180 ° to remove the upper silicon mold 11 (see FIG. 2E).

A gate metal 21 is deposited on the entire structure (see FIG. 2F).

After the photoresist was applied to the superstructure, it was ashed to expose only the metal on the tip (see Figure 2g).

The gate metal 21 and the gate oxide film 17 are sequentially etched using the photoresist film 23 as a mask, and the remaining photoresist film 23 is removed to expose the tip 25 to complete the device.

As described above, when the Al metal deposited on the silicon substrate is heat-treated according to the method of the present invention, silicon is melted into the Al metal, thereby applying the tip to the FEA manufacturing process, thereby easily forming a tip without a mask. At the same time, there is a feature that can adjust the shape of the tip according to the heat treatment temperature, and enables the large-area FEA manufacturing.

Claims (2)

Depositing Al metal on the silicon substrate; Heat-treating the deposited Al metal to form spikes on a silicon substrate; After removing the deposited Al metal, forming a thermal oxide film on the exposed silicon surface; Depositing a cathode metal to a predetermined thickness on the entire structure; Rotating the entire structure by 180 ° to remove the upper silicon mold; Depositing a gate metal over the entire structure, Applying a photoresist film to the upper portion of the structure and ashing to expose only the metal on the tip; Sequentially etching the gate metal and the gate oxide film using the photosensitive film as a mask; Method of manufacturing a FEA using a mold transfer technology, comprising the step of exposing the tip by removing the remaining photoresist. The method of claim 1, The width of the spike formed on the silicon substrate is a FEA forming method using a mold transfer technology, characterized in that 1.0 to 1.5㎛.