JPS58143528A - Dry etching method - Google Patents

Abstract

PURPOSE:To make possible high speed etching without etching the ground layer by a method wherein a gas is formed by substituting fluorine atoms of a gas of carbon fluoride series for hydrogen and gases chosen out of several inert gases and a gas estimating chamber is further provided. CONSTITUTION:A mask composed of resist 4 is formed on an SiO2 film 3 and, after a silicon substrate 2 is placed in an etching chamber 10, the inside of the etching chamber 10 is kept vacuous to the predetermined degree. A hydrogen substituted etching gas 6 and several inert gases 7, 8 are introduced in a pre- mixing chamber 9 and supplied to the etching chamber 10. A high frequency voltage is applied to generate plasma to etch the SiO2 film 3 by a neutral radical and ions. At this time, due to the effect of a hydrogen substituted gas of carbon fluoride series as a reaction gas, the SiO2 film 3 can be etched without etching the ground layers and further the effects of several inert gases (He, Ar, etc.) work to accelerate the etching of the SiO2 film 3.

Description

[Detailed description of the invention] The present invention relates to a dry etching method.

Neutral radicals and ions in the plasma are used for heat soap treatment (8LOs), vapor deposition method (CVD)-810, and polycrystalline silicon (BL).
), silicon nitride (5ilN4) + silicon nitride (silicone), etc. A dry etching method is available as a method for selectively etching.

In this dry etching method, as shown in Figure 1, a pair of parallel flat plates IE are separated from each other in an etching chamber.
During the period of 1k1, 2t of silicon substrates, which are manufactured in Australia, were placed in a container, gas was introduced into the etching chamber from the container 6, and a high frequency electric current was applied to the parallel plate electric ring 5. Then generate plasma and apply silicon ji & upper 2 resist 4.
This is to etch and remove gioaii13 that is not WC@.

In plasma, active atoms that are electrically neutral and have unpaired electrons t generate neutral radicals n5 and ionto molecules, and these neutral radicals n and ions 1 form B i O Yukiei 3 is etched. These neutral radicals n in plasma.

Ion 10 generation state 1 reaction i
, and because it depends greatly on the mixture condition of 7, conventional fluorocarbon thread gas (0njan + νKoshitomo. t7t, in the above method, the resist 40 serving as a mask also exhibits a so-called side etching (undercut) pattern dimension (the etching h1 pattern dimension is smaller than the mask) II phenomenon.
t0 An object of the present invention is to provide a dry etching method that is highly uniform and does not etch the underlayer 2, but can perform etching as per PI'l1iI.

In order to achieve such a purpose, one of the practical features of the present invention is to arrange the buds on the parallel plate electrodes, the neutral caries qII + ions, and the ions. In dry etching fi, the etching gas is a gas obtained by replacing the water volume of a carbon heptide-based gas O, and an excess of 1 gas from a number of inert gases, and roughly 5w5te of these male particles are used. This is the method of etching.

The following figure is a conceptual diagram of the dry etching method according to the present invention. −As shown in the figure,
In Etsuchinda Champa 10 indicated by [r! , a parallel plate electrode I is provided, and a predetermined a6 graviness is applied to this parallel plate electrode IK by a high frequency electric current 5. Such a device KT
o, on silicon ft41112 () 810mlem
When etching, first form a mask consisting of regimen 4 on the straw, then,
After putting a silicon group 1iZt into the etching chamber 10, the etching chamber 10 was set up as a real device with constant tSI, and the etching gas 6, I & 111, whose water volume was directly exchanged, was
i (D inert scum 7°8 was added to the premix 119, and this was supplied to the etching chamber 10 PIK.
Apply an IL voltage to generate plasma and etch gi=oll[ml by neutral radicals and io/.

At this time, due to the effect of the fluorinated R-fiber gas which replaced hydrogen in the reaction gas, etching was prevented (gi
osil13() etching is performed, and the effect of several kinds of inert gases (H, mul2, etc.) V810 = @
Etching increases by 1 position.

The etching characteristics of #iH gas and 0HF = gas are as shown in the table below. OK? Any using the high I gas O selectivity ratio,
Gas [H, t- added (oH1B+11m) gas is entered into the etching chamber as a gas, and etching is carried out under teplasm, making it possible to perform etching of 1 kJL by taking advantage of the advantages of 4-layer etching. In addition, by using H gas tt heat exclusively, it is possible to prevent the f-type resist from forming at a temperature of 9 eva.

Unexploded fIs can only be etched by the 4-substrate movement at high pressure due to the heating of these gases (JiiO).
*Etching of Il [This is a method of performing this, and it is also a method of forming a sharp etching pattern by preventing deterioration due to plasma thermal irradiation.

In the conventional zero-etching method, there was no way to etch the wrinkles at high speed without etching the underlying layer.

In addition, compared to etching with an inert gas, the etching pattern can be etched with water lI & substituted fluoride leg bulk yarn gas, making it possible to perform taper etching. By changing the volume of water to a secondary stage of fluorocarbon yarn gas, it is possible to perform Itll# with a pattern Ilr surface shape.

As described above, according to the present invention, it is possible to perform etching by passing without etching the underlying material, but by providing a convenient dry etching method for forming wrinkles in a four-pattern pattern.

[Brief explanation of drawings]

Figure M1 is a conceptual illustration of the apparatus used in the conventional dry etching method, and Figure 2 is a conceptual illustration of the apparatus used in the dry etching method according to one embodiment of the present invention C). Illustrated. ]...Parallel plate electrode, 2...Shi1nocon board, 3.
...S1O Elephant Edition,'...Resist, 5...Sho #1 Waveden-56...Hydrogen II Class Fluoride Carbon Thread Gases, 7.8
...Inert gases, 9...Premixing chamber, IO...Channo (.Il'IP,) Figure 1 Figure 2 Figure 1

Claims (1)

[Claims] 1. A space l arranged between a pair of parallel plate electrodes spaced apart from each other.
In dry etching method 5, the etching process is carried out using neutral radicals and ions generated between the electrodes by introducing l1l#mK gas'.
A dry etching method characterized in that at least 211 fli of gas consisting of a low etching gas and a gas with a high etching selectivity is used. 2. Australia's lump W is one cow oxidation wisdom, H. Gasquet is a gas with high etching speed, OHF is a gas with a high selection ratio, gas Description q)
Dry etching method.