JPH0665731A - Apparatus for production of semiconductor - Google Patents

Abstract

PURPOSE:To prevent the peeling of the deposits from a collimator and to improve the reliability of a wafer at the time of sticking the metal to be deposited onto the wafer by collimation sputtering. CONSTITUTION:A negative bias is impressed to a target 1, by which sputtering is started. The metal 8 which is to be deposited and is injected from the target 1 jumps out in random directions. This metal 8 to be deposited is controlled in the directions by the collimator 7 en route. The metal partly adheres to the collimator 7 and partly passes the collimator and sticks onto the wafer 2. The surface of the collimator 7a in this collimation sputtering is coated 7b with the same material as the metal 8 to the deposited. The metal 8 to be deposited, therefore, sticks well and the particles spraying to the wafer 2 by peeling decrease. The high-reliability semiconductor is thus obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to collimation sputtering.

[0002]

2. Description of the Related Art With the recent high integration and miniaturization of semiconductor devices, contact holes and through holes for electrically connecting elements are very small and have a high aspect ratio (contact diameter and contact diameter). Depth ratio). Usually, the metal wiring connecting the elements is formed by the sputtering method, but the step coverage, so-called step coverage, has become a serious problem for high aspect contacts.

Therefore, a technique used to improve the poor step coverage due to this sputtering is collimation sputtering. FIG. 3 is a cross-sectional view showing a schematic configuration of a sputtering chamber when performing collimation sputtering. In the drawing, 1 is a target made of titanium (Ti), which is a metal to be adhered, 2 is a wafer, 3 is a collimator provided between the target 1 and the wafer 2, 4 is a vacuum container having an exhaust hole 4a and accommodating the whole. Chamber of the
5 is a shield provided along the inner surface of the chamber 4, 6
Is a shutter arranged between the target 1 and the collimator 3. Note that FIG. 4 shows a schematic diagram of the collimation sputtering in A, and an enlarged view of the honeycomb-shaped mesh of the collimator in B.

Next, the operation will be described. When depositing titanium nitride (TiN), a desired ratio of nitrogen gas (N ₂ gas) and argon gas (Ar gas) (ArN ₂ = 0 to 50/100 to 50) and desired pressure ( Usually up to a few mTorr). When a negative bias (usually about -500 U) is applied to the target 1 in this normal state, sputtering is started. The process time is controlled by the shutter 6, and the Ti atoms emitted from the target 1 react with N ₂ and travel toward the wafer 2 as TiN. The direction of the TiN molecules is controlled by the collimator 3 on the way, and only the molecules of the vertical component are incident and attached to the wafer. Naturally, many TiN molecules adhere to the collimator 3 and form a film on the collimator 3. According to the observation result (not shown) sampled in the surface portion 3a, the intermediate portion 3b, and the back surface portion 3c, the adhesion state is particularly large on the back surface portion 3c, and the adhesion force is weak and peeling easily occurs. This is because the TiN molecule is the target 1 when passing through the collimator 3.
This is because TiN having high energy adheres to the surface portion 3a on the side thereof, whereas TiN having high energy adheres to the rear surface portion 3c on the side of the wafer 2 in a state of low energy due to scattering several times inside the collimator 3.

FIG. 5 is a graph showing the number of particle dust particles on the wafer 2 when a TiN film is formed by conventional collimation sputtering. The horizontal axis shows the number of processed wafers and the vertical axis shows the number of particles. There is. It can be seen that the number of particles on the wafer 2 rapidly increases as the number of processed wafers increases.

[0006]

Since the collimation sputtering in the conventional semiconductor manufacturing apparatus is performed as described above, the number of particles from the back surface of the collimator increases, and pattern defects (disconnection short circuit) occur on the metal wiring on the wafer. Not only does this occur, but the reliability of the wiring, and thus of the semiconductor device itself, deteriorates.

The present invention has been made to solve the above problems, and an object thereof is to obtain a highly reliable semiconductor manufacturing apparatus in which particles are less likely to be generated by collimation sputtering.

[0008]

In a semiconductor manufacturing apparatus according to the present invention, a collimator for directing an adhered metal adhered to a wafer has at least a surface in contact with the adhered metal made of the same material as the adhered metal. Is.

[0009]

In the semiconductor manufacturing apparatus according to the present invention, the same material as the adhered metal forming the surface of the collimator improves the adhesion to the adhered metal and reduces particles that are separated and scattered.

[0010]

【Example】

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing a schematic configuration of a semiconductor manufacturing apparatus according to Embodiment 1 of the present invention, in which A shows the entire sputtering chamber and B shows a partially enlarged collimator. In the figure, reference numerals 1, 2, 4 to 6 are the same as the conventional ones, and the description thereof is omitted. Reference numeral 7 denotes a collimator body 7a made of, for example, stainless steel (SUS), and a coating material made of the same material as the material of the target 1 that covers the surface of the collimator body, that is, the metal to be adhered, here, a Ti coating 7b. 8 is metal particles of the adhered metal, here TiN
The locus is indicated by 9 in the molecule.

Next, the operation will be described. Normally, the sputtering method is performed by applying a negative bias to the target 1 and establishing a plasma between the target 2 and the wafer 2. Since the wafer 2, the shield 5, and the shutter 6 are grounded, all argon ions and nitrogen ions in the plasma go to the target 1. When the argon ions collide with the target 1, the target 1
The atoms that make up pop out in random directions. In Example 1, nitrogen gas was mixed with argon gas to Ti.
Reactive sputtering to form an N film was shown, but in this case, the nitrogen ions are T
It reacts with i to become TiN and adheres to the wafer 2. Figure 1-B
FIG. 4 is a partially enlarged view of the collimator 7. The collimator 7 is also electrically grounded. Part of the TiN molecules 8 formed in the vicinity of the target 1 or in the vapor phase adheres to the collimator 7, and part of the TiN molecule 8 passes through the collimator 7 and adheres to the wafer 3. The TiN adhering to the collimator 7 adheres in a particularly low energy state on the wafer 2 side, so that the adhesion strength generally decreases and peeling tends to occur easily. However, TiN or Ti which has a very good adhesion with Ti is coated. Since the collimator 7 is used, Ti with low energy
The adhesion of N molecules is also very good.

FIG. 2 is a graph showing the results of particles in the case of implementation with this configuration. This graph is obtained by measuring particles in or on the film when TiN is deposited on the wafer by collimation sputtering to a thickness of about 1000 angstroms using a laser light scattering type particle counter. In the conventional example FIG. 5, the number of particles suddenly increases from the 10th sheet to a maximum of 0.8 particles / cm ² , whereas in this case the 50th sheet has 0.2 particles / cm ² and 1
It was confirmed that the number was decreased to / 4 or less.

Example 2. In the first embodiment, the case where TiN is sputtered and the case where the collimator is coated with Ti has been described, but the present invention is also applicable to the case where Ti is sputtered. In addition, the collimator is TiW or Ti
When coating with Ti / TiW, the collimator is Ti / Al engaging gold or Al when spattering TiW.
Al when the engagement gold is coated, when Al engagement gold is sputtered, when the collimator is W, or when Ti / W or Ti / TiW / W is coated, W spatter, when the collimator is coated by WSix, WSix sputter Can be applied to each. Generally, if the same material as the target material is coated on the entire surface of the collimator, the same particle reduction effect can be obtained.

Example 3. Although the first and second embodiments describe the case where the collimator made of stainless steel or the like is coated with the same material as the target material,
The same effect can be obtained when the collimator itself is made of the same material as the target material. For example, if the collimator is made of Ti without coating,
It is possible to reduce particles during TiN and Ti sputtering.

Example 4. In Examples 1 to 3, the case of the apparatus by the sputtering method was described, but it is also applicable to the apparatus by the vapor deposition method, and in this case, the collimator for arranging the directionality of the vapor deposition metal which is the metal to be deposited and is placed in the vacuum container, If all surfaces contacting the vapor deposition metal are coated with the same material as the vapor deposition metal, or if the collimator is made of the same material as the vapor deposition metal, it is possible to obtain the same effect as each of the above embodiments.

[0016]

As described above, according to the present invention, since the collimator for directing the adhered metal adhered to the wafer has at least the surface in contact with the adhered metal made of the same material as the adhered metal, the collimator adheres to the collimator. There is an effect that the adhered metal has a strong adhesiveness, is less likely to be peeled off and scattered on the wafer, and a highly reliable semiconductor manufacturing apparatus can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a semiconductor manufacturing apparatus according to a first embodiment of the present invention, in which A is an overall configuration diagram of a sputtering chamber and B is a partially enlarged view of a collimator.

FIG. 2 is a graph showing a result of particle generation according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a schematic configuration of a conventional semiconductor manufacturing apparatus.

4 is a schematic diagram of the collimation in FIG. 3, in which A is a collimation situation diagram and B is a honeycomb mesh of the collimator.

FIG. 5 is a graph showing a result of particle generation in a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 1 Target 2 Wafer 4 Vacuum Container (Chamber) 7 Collimator 7a Collimator Main Body 7b Coating Material (Same Material as Metal to Be Adhered) 8 Metal to Adhere

Claims (2)

[Claims] 1. A semiconductor manufacturing apparatus, comprising: a collimator for directing a metal to be adhered, for adhering the metal to be adhered onto a wafer, wherein the collimator is made of the same material as the metal to be adhered at least on a surface in contact with the metal to be adhered. A semiconductor manufacturing apparatus characterized by being configured. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the collimator has the entire surface in contact with the metal to be adhered coated with the same material as the metal to be adhered.