JPH0320607A - Minute-size measureing method - Google Patents

Abstract

PURPOSE:To make it possible to perform accurate measurement when the chemical compositions of materials are different by projecting an electron beam on the material to be measured, and measuring the size of a pattern from the Auger electron profile of the specified element discharged from the surface of the material. CONSTITUTION:A silicon dioxde film 2 is formed to a thickness of about 1,000 Angstrom on a semiconductor substrate 1 by thermal oxidation. Thereafter, positive resist is applied to the film thickness of about 1mum by rotation. Then, a part of the positive resist 3 is removed, and the positive resist layer in the desired minute pattern is formed, Then, an electron beam whose diameter is narrowed down to about 0.3mum is projected on the surface so as to scan the surface. At this time, the Auger electrons discharged from the surface of a sample are captured. The distribution of the contents of carbon is plotted. In a profile 4 of carbon obtained in this way, the intensity (a) becomes high at a part corre sponding to the positive resist 3. Rise-up and fall-down of a signal are shown at the boundary with a part corresponding to the silicon film 2. The distance from the rise-up point to a point where the signal falls down and the carbon is not detected is a size 5 of the positive resist 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for measuring minute dimensions based on the Auger electron profile of a specific element emitted from a surface by irradiating an electron beam.

Conventional technology As the miniaturization of semiconductor devices progresses, and the minimum dimensions become submicron standards of 1 μm or less, quality control in the manufacturing process, especially dimensional control in each screen process, becomes important. It becomes. BACKGROUND OF THE INVENTION In place of optical length measuring devices, length measuring SEMs (scanning electron microscopes) are increasingly being used to measure pattern dimensions in the manufacturing process of semiconductor devices, which are becoming increasingly finer.

Problems to be Solved by the Invention When a CD-SEM is used, dimensions are measured based on information from secondary electrons. In the measurement of rtcs=h, there is a problem that the contrast of the secondary electron image is difficult to obtain and the boundaries of the pattern are difficult to distinguish.

The present invention solves the above problems and provides an accurate method for measuring minute dimensions.

Means for Solving the Problems In order to solve the above problems, the present invention irradiates a material to be measured with an electron beam and measures dimensions based on the profile of Auger electrons of a specific element emitted from the surface of the material. .

The method described above can also be used to measure the dimensions of a high-resistance pattern formed on a high-resistance film, using the Auger electron profile to accurately measure the dimensions of a high-resistance pattern formed on a high-resistance film. Dimension measurement becomes possible.

EXAMPLES Hereinafter, examples of the method for measuring dimensions of micropatterns according to the present invention will be described in detail with reference to the drawings.

FIG. 1(a), Φ) is a cross-sectional view of a pattern to be measured and an Auger electron profile of carbon, showing an embodiment of the present invention. The pattern to be measured shown in FIG. 1(a) is obtained by applying a silicon dioxide film 2 on a semiconductor substrate by thermal oxidation for approximately 1000 times, then applying a positive resist 3 to a thickness of approximately 1 μm, and then applying a positive resist 3 to a thickness of approximately 1 μm. A portion of the resist layer is removed to form a positive resist layer with a desired fine pattern.

Next, an electron beam with a beam diameter reduced to approximately α3 μm is scanned toward this surface. At this time, Auger electrons emitted from the sample surface are captured and the carbon content distribution is displayed on a chart. As shown in Figure 1 (03), the carbon profile obtained in this way has a strong intensity at the part corresponding to the positive resist 3, and a signal rises at the border with the part corresponding to the silicon dioxide film 2. , and a falling edge can be seen. The distance from the rising point where carbon is detected to the point 1 where the signal falls and carbon is no longer detected is the dimension of the positive resist 3.

Effects of the Invention According to the present invention, even in cases where it is difficult to measure using a conventional length measurement SEM, as long as the chemical composition of the materials is different, very accurate measurement is possible. Measurement becomes extremely easy.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of the pattern to be measured, and FIG. 1(b) is an Auger electron profile of carbon. 1... Semiconductor substrate, 2... Silicon dioxide film (S102), 3... Positive resin, 4... Auger electron (carbon) profile, 5...Positive dimensions.

Claims (1)

[Claims] A micro-dimensional measurement method that measures pattern dimensions based on the Auger electron profile of a specific element emitted from the surface of a material to be measured by irradiating the material with an electron beam.