JPS59114820A - Formation of pattern - Google Patents

Abstract

PURPOSE:To improve the sensitivity of resist and the productivity thereof by heating the resist on a substrate followed by the irradiation of electron beam to the heated resist while keeping a predetermined temperature. CONSTITUTION:As a resist, PMMA, for example, is coated on an Si substrate by spin-coating method. Next, the Si substrate coated with the resist of PMMA is inserted into a container in vacuum, where the resist on the substrate is heated to the temperature of about 80-100 deg.C by a heater in vacuum. Thus heated Si wafer is carried to an electron beam exposing device connected to the vacuum container and is held on a heating stage in the container. Then, the electron beams are made to irradiate with keeping the temperature at 90 deg.C and development is done so as to obtain a desired pattern. A derivative of PMMA in addition to PMMA is also available for a resist.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a pattern forming method, and particularly relates to a pattern forming method that increases productivity by increasing the sensitivity of the same resist by heating.

(2) Technical Background As semiconductor devices such as ICs and LSIs become more densely packed, the establishment of microfabrication technology has become more important. In the processing technology, phosphorography has been used in the past, in which a pattern is formed entirely on a semiconductor substrate by utilizing the reactivity and solubility of a polymer, and the substrate is processed using the pattern as a mask. In phosphorography, in order to obtain high resolution, electron beams, which are high-energy beams with small diffraction and scattering effects, are used as energy sources for polymer reactions, in addition to conventional ultraviolet rays.

(3) Prior Art and Problems Conventionally, when forming a pattern using an electron beam, a resist material such as PMMA (polymethyl methacrylate) or PBS (polybutene sulfone) has been used as a resist.

However, for example, the electron beam sensitivity of the above PMMA is 5X1
0-' to 10xlO-' c/lri, and 1 normal resist sensitivity lXl0-' to 10 x 10-'
This is a low value compared to c/cdl. As described above, if the sensitivity of the resist is poor, the exposure time, development time, and productivity will decrease.

(4) Purpose of the Invention In view of the above drawbacks, the present invention provides a pattern forming method that increases resist sensitivity.

That is, the object is to provide a pattern forming method that improves productivity.

(5) Structure of the Invention The object of the present invention is to provide a pattern forming method comprising a step of irradiating a resist on a semiconductor substrate with an electron beam.

This is achieved by a pattern forming method comprising the steps of: first heating the resist on the conductive substrate; and then irradiating the heated resist with the electron beam while keeping the heated resist at a predetermined temperature.

(6) Examples of the invention The present invention will be explained below based on examples.

PMMA eo as a resist on a silicon substrate, 8~
The PMMA was coated by a 1.2 μ spin code method and then
A silicon substrate coated with a resist of approximately I
It was inserted into a vacuum container at 7 Torr, and heated by a heater in the vacuum to a temperature of 80 to 100° C., which corresponds to the resist sensitivity on the substrate. The heating time was about 10-20 degrees. The silicon wafer heated in this way is moved to the electron beam fiber optic device connected to the vacuum container mentioned above, held on a heating stage in the device, and irradiated with electrons m while maintaining the temperature at 90°C to develop it. By doing this, the desired pattern could be obtained. The electron beam irradiation conditions were an acceleration voltage of 20 KV. As a result, the sensitivity of PMMA 5-10X10=c/c
dl can be obtained, and the sensitivity of conventional PMMA is 5 ×
An improvement of about one order of magnitude compared to 10-Itc/crd was found.

Furthermore, it has been found that as the sensitivity of PMMA improves, the patterning time by EB is shortened and productivity is improved.

The heating temperature range of the resist in the present invention is defined by the Ty of the polymer used.

In addition to PMMA, derivatives thereof may be used as the resist according to the present invention. For example, its derivative is (-0f-12-
0-0f-12su0 (Y X= ON, NO2, OF3.] Hit Gen, 0t13
+Alkylbenzene ring+NH2,000t4. 5i
t-]3Y=alkyl, haloalkyl, H, norogen, and benzene ring.

(7) As described in detail of the invention, according to the notch turn forming method according to the present invention, the sensitivity of the resist can be improved and the productivity can be improved.

Claims (1)

[Claims] 1. A pattern forming method comprising the step of irradiating a resist on a semiconductor substrate with an electron beam, heating the resist material on the semiconductor substrate, and then keeping the heated resist at a predetermined temperature. A pattern forming method comprising the step of irradiating the electron beam. 2. The pattern forming method according to claim 1, wherein the resist is polymethyl methacrylate or a derivative thereof. 3: The pattern forming method according to claim 1 or 2, wherein the heating temperature of the resist is 80 to 100°C.