JPS63110638A - Semiconductor manufacturing method - Google Patents

Abstract

PURPOSE:To contrive to perform an etching of low damage at high throughput by a method wherein a high-speed etching is performed in a plasma generating chamber until the midst of an etching process and from immediately before the end point of the etching process, a sample stand is shifted from the plasma generating chamber and a reactive ion etching (RIBE) of low damage is performed. CONSTITUTION:A movable sample stage 11 with a sample 3 installed thereon is set in a reaction tank 1 for holding plasma, plasma is generated in the plasma generating tank 1 and a high-speed etching is performed. In the midst of this etching, the movable sample stage 11 is made to shift plasma generating chamber 1 and an RIBE is performed. Hereupon, an electron cycloton resonance is generated by the interaction between magnetic fields generated by magnetic coils 7 and microwaves 8, neutral particles are ionized by electron impact and ions are generated. These ions are directed onto the lead-out sample 3 as ion beams 10 and the sample 3 is etched. The ion beams 10 obtainable at this time can be controlled at low energy and damage to the sample 3 can be lessened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor manufacturing method, and particularly to a method for microfabrication of semiconductor elements by etching.

[Conventional technology]

Conventionally, reactive ion etching (hereinafter referred to as RIB) has been widely used for microfabrication in the manufacture of semiconductor devices. Fig. 2 is a cross-sectional view for explaining the RIFj method. A gas introduction system (5) is an exhaust system for maintaining a predetermined gas pressure in the plasma generation chamber 11) while introducing gas through the gas introduction system 141.

Next, the principle from R will be explained. Gas introduction system (4)
While introducing gas, exhaust is performed by the exhaust system +61, and the plasma generation chamber +11'i is maintained at a predetermined pressure.

When high frequency power is applied to electrode +21, a plasma noise generation chamber...
Plasma is generated inside. The sample exposed to plasma is constantly bombarded with particles consisting of excited neutral particles, electrons, and ions, and the sample (3) is etched by a chemical reaction.

In this case, since the ions are accelerated perpendicularly to the sample by the ion sheath, anisotropic etching is performed and fine patterns can be formed.

In addition, there is currently a method of etching by irradiating a sample with reactive ions in the form of a beam, so-called reactive ion beam etching C.

(referred to as E rather than R) technology has been developed. Figure 8 is Satoshi:
FIG. 2 is a cross-sectional view illustrating a method of E from R using a child cyclotron resonance (hereinafter referred to as KCR) type ion source;
In the figure, 161 is a sample stage, (1) is a magnetic coil for generating a magnetic field, (8) is a microwave wave, [91
fi ion generation chamber, (lO) is the ion beam extracted from the ion generation chamber (91) Next, the principle of RIBE using KCR will be explained. Electrons are caused to move in a spiral manner and are accelerated at a high rate under ECR conditions.For this reason, the probability of separation of neutral particles due to electron impact increases in the ion generation chamber (9), and highly ionized plasma is formed. be done.

Ion beam (1
The sample (3) is etched by irradiating the sample 13) with 0).

[Problem that the invention seeks to solve]

Conventional R Engineering E [With the above structure, the sample exposed to plasma is constantly bombarded by ions with high energy (sometimes reaching several hundred eV) as shown in Figure 4. However, there was a problem that the sample could be damaged.

On the other hand, as shown in FIG.
Although the damage to the sample is reduced because the etching can be performed at a lower level, there is a problem in that the gas pressure during etching is lower than that in RE process E, resulting in a lower etching rate.

The present invention was made to solve the above-mentioned problems, and its object is to provide a complete semiconductor manufacturing method that can reduce damage to a sample and perform high-speed etching.

[Means for solving problems]

In the semiconductor manufacturing method according to the present invention, high-speed etching is performed in a plasma generation chamber until the etching process is cooled, and from one page before the etching end point, the sample stage is moved from the plasma generation chamber to perform RIBE with less damage. This is the method I used.

[Effect]

In this invention, the sample stage can be moved from the plasma generation chamber.
Plasma etching followed by RI
BK is performed, allowing for high throughput and low damage etching.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a semiconductor manufacturing method according to an embodiment of the present invention. In the figure, +3) is a sample, and (11) is a movability for moving a sample 13) from a plasma generation chamber to conduct R1Bln gold. sample stage, (force and (8) are respectively F,
magnetic coil and microwave to cause CR discharge,
+101 is an ion beam extracted from ions generated by KCR discharge in a plasma generation chamber.

Instead, plasma etching is performed in FIG. 1al. The movable sample stage (II) with the sample (3) attached is set in the reaction tank (1) for holding the glaze, and the gas introduction system (4
1, the etching gas is evacuated by the exhaust system (6) while four people are in use, and the plasma generation tank 11+ is maintained at a predetermined pressure. By applying a magnetic field and microwave (8)k, plasma arm generation H1tll is positive! occurs. The sample (3) exposed to the plasma is rapidly etched by a chemical reaction with neutral excited particles. At this time, the sample stage (1
Anisotropic etching is possible by applying an RF bias to 1). Next, the plasma etching is finished by cooling the etching process, and the movable sample stage (1) is moved to the position shown in Figure 1, 1al.
As shown in 1, the plasma is transferred from the plasma generation chamber 11 and Fi is performed from R. No. 1 (magnetic coil tel in bl)
Electron cyclotron resonance due to interaction between magnetic field and microwave +81? The electron bombardment causes the neutral particles to ionize and generate ions. The sample (3) is etched by irradiating the extracted sample (3) with this ion beam (lO).

Ion beam tloli20~30e obtained at this time
It is possible to control V and low energy VC, thereby making it possible to reduce damage to the sample (3).

As you can see from the above explanation, this is an example of an IC book.

Two high-speed etching steps are performed in the plasma generation chamber until the end of etching.
Since the RIBFXi was performed with the E-movement, high-speed etching with little damage to the device could be performed.

In addition, in the above example, ECR type ion g is set as E rather than R.
T? Although the present invention is not limited to this example, the present invention is not limited to this, but the present invention is not limited to this, and the invention is not limited to this. The i3T function can also be applied to photo-assisted etching in which etching is performed by promoting the reaction only where it hits.

〔Effect of the invention〕

As described above, according to the present invention, since the sample stage can be moved during etching, it is possible to perform etching with high throughput and low damage.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a semiconductor manufacturing method according to an embodiment of the present invention, FIG. 2 is a sectional view showing a conventional RIE method,
Figure 8 is a cross-sectional view of the conventional RIBIIH method for cooling water.
The figure is a distribution diagram of ion energy. ] 11 is a plasma generation chamber, 13) is a sample, no+ is an ion beam, (River is a movable sample stage. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) After the upper layer of the portion of the semiconductor device to be removed is removed by first reactive ion etching, a second reactive ion etching process is performed using a second reactive ion etching process that has a lower etching rate and less damage than the first reactive ion etching process. A semiconductor manufacturing method characterized in that the remaining portion of the portion is removed by ion etching. (2) The semiconductor manufacturing method according to claim 1, wherein the first reactive ion etching is realized by magnetic field microwave discharge plasma. (3) A reactive ion beam using a plasma generated by an electron cyclotron resonance phenomenon as an ion source
4. The semiconductor manufacturing method according to claim 1, wherein reactive ion etching is performed.