KR20000046070A - Ionized metal plasma apparatus - Google Patents

Abstract

PURPOSE: An ionized metal plasma apparatus is provided to improve a straight moving ability of a metal atom, thereby providing a layer covering property to a contact base portion of a semiconductor having a high aspect ratio. CONSTITUTION: An ionized metal plasma apparatus consists of a target(21), a collimator(26), a high frequency coil(22) and a wafer(24). The target(21) is formed of a metal material to be deposited on a wafer in a chamber(20) and the target sputters metal atoms by a DC magnetron(23). The collimator(26) improves a straight moving ability of the metal ions. The high frequency coil(22) on which a high frequency electric power is exerted changes the metal atoms having improved straight moving ability into an ion state. And the wafer(24) on which the metal ions changed by the high frequency coil are deposited by an electric potential difference with the DC magnetron when the high frequency electric power is exerted. The target is formed of one metal material out of aluminum, titanium and copper.

Description

Ionized metal plasma apparatus

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ionized metal plasma (IMP) devices, and in particular to adding a collimator to the interior of the IMP device to improve the straightness of the atoms before the sputtered atoms are ionized to form a layer of contact base. An IMP device that can improve covering and layer covering uniformity.

The most advanced method for improving the layer covering of the contact base portion during the manufacturing process of the semiconductor device is a method using IMP. This method improves layer coverage by ionizing sputtered atoms and then pulling them with electrical force towards the wafer. A schematic of the equipment used for this method is shown in FIG. It is shown in Figure 1 (b).

First, referring to Figure 1 (a) will be described the configuration of the conventional IMP equipment as follows.

A target 11 made of a metal material to be deposited on the wafer 14 is installed inside the chamber 10 to sputter metal atoms by a DC magnetron 13. The metal atoms sputtered from the target 11 are brought into an ionic state by an RF coil 12 to which RF power is applied. The wafer 14 is supported by the wafer chuck 15, metal ions are deposited by the high frequency coil, and RF power is applied to be different from the voltage applied to the target, thereby improving the linearity of the metal ions. Let's do it.

As shown in FIG. 1B, sputtered metal atoms in the conventional IMP apparatus are ionized under the influence of RF power applied to an RF coil, and these ions are electrically driven toward the wafer by RF power formed by wafer bias. Receive straightness increases. However, due to the momentum of the sputtered atoms, the direction is determined by the sum of the vectors, which is why ions with perfect straightness are only possible if the atoms go straight from the beginning. In addition, the rate of ionization by the RF power applied to the RF coil is generally less than 60%, depending on the DC magnetron, the RF coil, and the internal pressure. In this situation, when the contact hole is deep, the layer covering characteristic is weak at the center portion of the contact hole, and the center portion is deposited in a thick form at the base of the contact hole.

In order to solve this problem, a method of increasing the electrical force to have more straightness may be used. However, if the electrical force is too strong, there is a problem in that sputtering occurs on the wafer, which makes it difficult to control the process. Therefore, there is a limit in applying the electrical force, and the momentum of the initial sputtered atoms still remains, so that it is difficult to obtain full straightness. Another problem is that not all sputtered atoms are ionized, and the proportion of neutral atoms is quite large. Therefore, these neutral atoms do not contribute to layer covering because they are deposited in different directions as in the normal sputtering method.

Accordingly, an object of the present invention is to provide an IMP device capable of improving the linearity of metal ions and having a complete layer covering property on a contact base of a semiconductor device having a high aspect ratio.

The present invention for achieving the above object is made of a metal material to be deposited inside the chamber to be deposited on the wafer, a target for sputtering metal atoms by a direct-current magnetron, a collimator for improving the straightness of the sputtered metal atoms, A wafer on which a high frequency coil is applied to make a metal atom having improved linearity by the collimator into an ion state, and a wafer on which a metal ion converted by the high frequency coil is deposited by applying a high frequency power to a potential difference between the DC magnetron. Characterized in that comprises a.

1 (a) and 1 (b) are schematic diagrams of a conventional IMP apparatus and a diagram for explaining the direction of ions thereby.

2 (a) and 2 (b) are schematic diagrams of an IMP apparatus according to the present invention and a diagram illustrating the direction of ions thereby.

<Description of Signs of Major Parts of Drawings>

10 and 20: chambers 11 and 21: targets

12 and 22: high frequency coil 13 and 23: DC magnetron

14 and 24: wafer 15 and 25: wafer chuck

26: collimator

The present invention will be described in detail with reference to the accompanying drawings.

2 (a) and 2 (b) are schematic diagrams illustrating the IMP device according to the present invention and a direction of movement of metal ions thereby, and with reference to FIG. 2 (a), FIG. The configuration is as follows.

A target 21 made of a metal material to be deposited on the wafer 24 is installed inside the chamber 20 to sputter metal atoms by a DC magnetron 23. As the target 21, a metal material such as aluminum (Al), titanium (Ti), copper (Cu), or titanium silicide (TiSi ₂ ) is used. The metal atom sputtered from the target 21 improves linearity by the collimator 26. In addition, the collimator 26 is electrically isolated to prevent the electrons of the metal atoms from escaping out of the DC magnetron 23, thereby improving the density. As a material of the collimator 26, titanium is used when a target is used, and when another metal is used as a target, the titanium is made of titanium and then coated with a material of the target metal. On the other hand, the collimator 26 is used by attaching a support to the shield (shield) and put it on or directly attached to the shield. Metal atoms whose straightness is improved by the collimator 26 are brought into an ionic state by an RF coil 22 to which RF power is applied. The wafer 24 is supported by the wafer chuck 25, and metal ions are deposited by the high frequency coil. In addition, since a difference with the voltage applied to the target is generated by the RF power applied to the wafer 24, the linearity of the metal ions is improved to facilitate the formation of the metal layer on the contact base formed on the wafer 24. do.

In the present invention, as shown in FIG. Since the sputtered atoms are improved in advance, the linearity of ions is improved by being attracted by the electrical force due to the wafer bias after ionization, and thus the linearity of ions is greatly improved by being attracted by the electrical force due to the wafer bias power even after ionization. In addition, since the straightness of the neutral atoms is improved by the collimator, the layer covering property of the contact base may be improved, and the uniformity of the layer covering may be greatly improved.

As described above, according to the present invention, the layer covering property of the contact base can be improved and the layer covering uniformity can be improved by primarily depositing, ionizing and depositing the linearity of the metal atoms by the collimator. Accordingly, the thin film can be stably and uniformly deposited even in a contact having an aspect ratio of 10 or more, thereby ensuring stability of device operation.

Claims (4)

A target which is installed inside the chamber and is made of a metal material to be deposited on a wafer to sputter metal atoms by DC magnetron; A collimator for improving the straightness of the sputtered metal atoms, A high frequency coil for applying a high frequency power to bring the metal atoms of the linearity improved by the collimator into an ion state, And a wafer on which high-frequency power is applied to deposit metal ions converted by the high-frequency coil by a potential difference with the direct-current magnetron. The ionization metal plasma apparatus of claim 1, wherein the target is made of a metal material of any one of aluminum, titanium, copper, and titanium silicide. The ionizing metal plasma apparatus of claim 1, wherein the collimator uses titanium when using titanium as a target, and when titanium is used as a target, coating the titanium material with a target metal. The ionization metal plasma apparatus of claim 1, wherein the collimator is used by attaching a support to the shield and placing the support thereon or directly attaching the shield.