WO1989007335A1

WO1989007335A1 - Improved etching method for photoresists or polymers

Info

Publication number: WO1989007335A1
Application number: PCT/US1989/000286
Authority: WO
Inventors: Narcinda R. Lerner; Theodore J. Wydeven, Jr.
Original assignee: The Government Of The United States As Represented
Priority date: 1988-01-29
Filing date: 1989-01-30
Publication date: 1989-08-10

Abstract

The present invention relates to an improved method for dry etching and/or thinning polymers, stripping photoresists from semiconductors, or removing the volatile organic matter of residue from substrates. Three related sets of conditions are disclosed. First, a plasma discharge is contacted with a reactive gas then the gas is contacted with a sacrificial non-metallic chemical source (13A) in the afterglow of the plasma discharge, producing a reactive gas species which etches the material (13) to be etched. Second, a reactive gas and the sacrificial non-metallic chemical source (13A) are simultaneously contacted with a plasma discharge producing a reactive gas species which etches the material (13) to be etched. Third, a reactive gas is directly irradiated using ultraviolet radiation producing ultraviolet generated gas particles which when it contacts the sacrificial non-metallic chemical source (13A) and material (13) to be etched, produces a reactive gas species which etches the material (13) to be etched. The method is particularly useful in removing organic photoresists in semiconductor manufacture.

Description

IMPROVED ETCHING METHOD FOR PHOTORESISTS

OR POLYMERS

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an improved method and apparatus for dry etching and/or thinning polymers, stripping photoresists from semiconductors, and removing the organic matter or residue from substrates. Specifically, the method concerns using a reactive gas and a sacrificial non-volatile organic solid as reactants to react in the afterglow of a plasma glow discharge, using a reactive gas and a sacrificial polymer in the plasma discharge itself, or directly irradiating a gas with ultraviolet radiation wherein the products produce a highly reactive gas mixture which react with the sacrificial polymer to produce the etching agent for polymers or other organic or inorganic materials. Description of Related Art

A common etching or thinning procedure for polymers or photoresists using a plasma or glow discharge involves placing the sample to be' etched directly in the glow of the discharge. A major disadvantage of this procedure is that it results in the sample being exposed to highly energetic ions, electrons, photons and electric fields which can result in substrate damage, especially if the substrate is a semiconductor or integrated circuit. Electrostatic breakdown causing significant damage to semiconductor devices has been observed under the harsh conditions encountered in plasmas during photoresist stripping using such a procedure.

Another approach is the etching of the substrate in the particles of the afterglow of a plasma discharge. However, as presently performed, this etching process is very slow.

K.Y. Ann et al in U.S. Patent No. 4,243,476 disclose a method for etching materials in which a solid located in the vicinity of the substrate, is used to provide reactive species for etching the substrate. In contrast with prior art etching techniques, an ion beam is provided which strikes a solid source located in the vicinity of the substrate. Reactive gas species are given off by the solid source when it is hit by the ion beam and these species etch the substrate. Etch rates can be enhanced or retarded depending upon the composition of the solid mask. Conductors and dielectrics can also be etched by this technique. This reported method relies on the use of an ion beam which directly strikes the solid source that surrounds the sample to be etched. In the present invention, the sample to be etched is placed at a remote location, well outside the region where a significant concentration of highly energetic ions might be encountered.

H. Komatsu et al in U.S. Patent 4,412,119, disclose a dry-etching method for working SiO₂ or the like by the use of a glow discharge plasma. The method involves the steps of introducing He, Ar, N₂, O₂ or mixtures of these gases into a reaction chamber from the outside and effecting the plasma discharge in the reaction chamber so that a reactive gas is liberated from a high molecular weight resin material arranged in the reaction chamber and containing fluorine atoms. This dry etching method requires and uses no expensive gas containing a fluorocarbon, but has sufficient etching rate and selectivity. A very important difference between this reported method and the present invention is that in Komatsu et al, the sample to be etched is placed within the plasma, i.e., in the energetic reaction chamber. In one of the embodiments of our invention described herein, the sacrificial polymer is placed within the plasma and the sample to be etched is placed at a remote location, well removed from the energetic plasma. The reference does not teach or suggest the exposure of a sacrificial polymer in the afterglow of a plasma discharge, also having the sample to be etched at a remote location from the plasma discharge.

J.L. Vossen, Jr., in the U.S. Patent No. 3,692,655 discloses a method for the radiofrequency sputter etching of a pattern defined by an organic photoresist mask. The mask is placed on the surface of a material from which there are dissociated under the conditions of a sputter etching, elements or complexes which are reactive with organic photoresist. The method includes backscattering of a relatively inert material to the photoresist to reduce degradation of the photoresist by the reactive elements or complexes. This reported method is intended to protect the photoresist from degradation. In contrast, the method of the present invention enhances the degradation of the photoresist or other organic matter which is present.

M. Tanno et al in U.S. Patent 4,612,099 disclose a reactive ion etching method. The apparatus to achieve the method includes a vacuum vessel, exhaust means, etching gas supply means, plasma generating electrodes, and high frequency power supply, and a substance having catalytic activity. The substance having catalytic activity is usually a volatile halogenated liquid which is inserted in the etching gas supply means which is subsequently subjected to a plasma discharge to improve the etching speed and selectivity. The use of a low vapor pressure solid being exposed in the afterglow of a plasma discharge is neither taught nor suggested.

W.S. Ruska discloses in Microelectronic Processing: An Introduction to the Manufacture of Integrated Circuits, published by the McGraw-Hill Book Company of New York, New York in 1987, which is incorporated herein by reference, many aspects of the process to produce integrated circuits. Specifically, in Chapter 6 "Etching", Ruska discusses a number of specific reaction conditions to obtain the etching. On page 221, he specifically discusses the loading effect of the etching process, as follows.

"One further complication of plasma etching is the loading effect. The rates of many reactions are found to depend on the area (A below) of substrate being etched: a greater exposed area to be etched slows down the reaction. This results from depletion of the reactive species from the plasma by the etch reaction. Consider an etch rate, with rate constant k, dependent on a reactive species with a lifetime in the plasma τ and a volume generation rate (e.g., in molecules per liters sec ^-1) G. Subject to some very plausible assumptions, the etch rate can be written as

where r is the etch rate, A the area of material being etched, and K is a constant determined by the reaction and the reactor geometry. It follows that r depends on A if the product of reaction rate and lifetime, kτ, becomes sufficiently large. A loading effect can be avoided by choosing a chemistry with a slow reaction rate or a short species lifetime. This, however, results in a decrease in the maximum etch rate, given by kτG, unless the species generation rate G can be made correspondingly large. The result is an unavoidable trade-off between reaction rate and loading effect.

Loading effect is intrinsically undesirable and becomes especially troublesome when good end-point control is crucial. As the etching becomes almost complete, the area being etched decreases rapidly towards zero. If there is a substantial loading effect, the etch rate rises rapidly, resulting in a runaway etching of the remaining volume. If the reaction possesses any isotropy, the result can be excessive undercutting caused by fast etching of the small exposed area at the sides of the cuts."

Contrary to the disclosure of Ruska, supra, which would lead one to expect that adding a nonvolatile organic solid to a reactor containing a material to be etched would decrease the etch rate of the material to be etched, the present invention achieves an enhanced etch rate by the addition of a sacrificial material to the etching chamber. Furthermore, the present invention provides a dry etchant which removes organic matter and/or polymers, including photoresists, rapidly from various substrates at room temperature, without exposing the polymer or substrate to the ions, electrons, photons and electric fields encountered in plasmas, and which does not involve the use of additional high pressure gas cylinders, or the use of hazardous or toxic materials which must be disposed.

SUMMARY OF INVENTION

The present invention relates to an improved method for etching a sample of a material using a reactive gas species, which method comprises the steps of:

(a) selecting reaction conditions from: (i) locating a sample of material to be etched in a gas atmosphere in close proximity of a sacrificial non-metallic chemical source having a very low vapor pressure which is capable of releasing a reactive gas species or a precursor to a reactive gas species, treating a reactive gas with a plasma glow discharge at a location remote from the material to be etched and non-metallic chemical source, and

- subjecting the material to be etched at the remote location and a non-metallic chemical source to the plasma generated gas particles of the afterglow of a plasma discharge under conditions effective to release a reactive gas species or a precursor to a reactive gas species which is conveyed to the material to be etched;

(ii) locating a sample to be etched at a remote location and a non-metallic chemical source directly in a plasma discharge or within the afterglow of a plasma discharge with a reactive gas under conditions which release a reactive gas species or a precursor to a reactive gas species, which is conveyed to the material to be etched, or

(iii) locating and subjecting the material to be etched and the non-metallic chemical source to the products obtained by subjecting a reactive gas to ultraviolet radiation under conditions which release a reactive gas species or the precursor to a reactive gas species which is conveyed to the material to be etched; and (b) etching the material to be etched with the released reactive gas species, which chemically reacts with the material to be etched to form volatile species that distill from said material to be etched, thereby causing etching of the material.

In one preferred embodiment, the sample to be etched and non-metallic chemical source are subjected to the afterglow of a plasma discharge [substep (i)]. In a preferred embodiment of this method, in step (a) of the material to be etched comprises an organic compound, the non-metallic chemical source is an organic compound comprising carbon and hydrogen atoms, having a vapor pressure of about 0.001 millimeters of mercury (Hg) or less, and a plasma glow discharge is generated at a remote location so that the sample to be etched and non-metallic chemical source are subjected to the afterglow of the plasma.

An object of the present invention is to provide an improved method of dry etching and thinning polymers, stripping photoresists from semiconductors, and removing or cleaning organic matter or residue from substrates. This method involves using a sacrificial non-volatile' organic solid as a reactant with plasma generated gas particles in the afterglow of a plasma discharge of a reactive gas to produce a highly reactive gas species mixture which is the etchant for polymers or organic matter.

It is also an object of the present invention to provide a method where the sacrificial polymer is exposed to the ultraviolet generated gas particles obtained by the ultraviolet irradiation of a reactive gas such as oxygen. The reactive gas species or the precursor to the reactive gas species produced is the active etchant.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a schematic of one embodiment of the apparatus of the etching equipment wherein the non-metallic chemical source is physically located on the top surface of the material to be etched. Figure 2 shows a schematic similar to Figure 1 of a second embodiment where the non-metallic chemical source (sacrificial material) and material to be etched are immediately adjacent to each other.

Figure 3 in views (a) to (e) show different spacial arrangements for the sacrificial material and the material to be etched.

Figure 4 shows a schematic of an embodiment of the invention wherein the energy to produce the ultraviolet generated gas particles is supplied by direct UV radiation of the reactive gas.

Figure 5 shows a cross-section of one configuration for the non-metallic material surrounding the material to be etched.

Figure 6 shows a cross-section of the sample holder for the sacrificial polymer and the sample to be etched.

Figure 7 shows a cross-section view of a sacrificial polymer surrounding the edge of the sample to be etched.

Figure 8A shows a top plan view where a number of samples as shown in Figure 5 are etched at the same time.

Figure 8B shows a top plan view wherein the sample to be etched (13E) and the sacrificial polymer (13F) are adjacent to each other.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS Definitions

As used herein:

"Material or sample to be etched" refers generally to an organic material substrate which is in need of etching or cleaning of part or all of the organic material in a manner in which the products of the etching or cleaning are volatile and are removed as gases. "Non-metallic chemical source" refers to the sacrificial material having a vapor pressure of less than 0.001 millimeters of Hg which in the presence of the products of the RF discharge in the gas react to produce the reactive gas species or the precursor to the reactive gas species. The terms "non-metallic chemical source," and "sacrificial material" or "sacrificial polymer" are often used interchangeably in this invention.

"Reactive gas" refers to the reactive gas which is used as a source for the plasma generated gas particles. Examples include fluorine, chlorine, oxygen, nitrogen, nitrous oxide, nitrogen dioxide, hydrogen or mixtures of these gases. Preferably, oxygen, nitrogen or mixtures thereof are used. More preferably oxygen is used.

"Plasma (ultraviolet) generated gas particles" refer to the short-lived particles of the gas produced in the electromagnetic discharge (e.g. glow discharge, UV, etc.). These particles react with the sacrificial non-metallic chemical source and produce volatile products, i.e. "reactive gas species" or precursors to the "reactive gas species," which etch the polymer to be etched.

In the present invention, a glow discharge plasma reactor 10 and 20 (referring to Figs. 1 and 2) with external electrodes 11 and 21 were used to generate plasma generated gas particles from oxygen gas 12. A variant of this reactor is shown in Figure 2. The important features of the reactor used for this procedure are: the electrodes 11 and 21 or region of plasma generation is separated from the sacrificial polymer 13A, sample to be etched (13) by a distance small enough to promote etching but not heat or destroy the sample to be etched (generally between about 5 and 50 cm, preferably about 16 cm). The reaction tube has an angle of between about 30 to 120° at point 14. Preferably, an angle of about 90° separates the sample 13 from the plasma. Under these conditions, exposure of the polymer 13 to ions, electrons, photons and electric fields is negligible. The power supply 15 for the electrodes is operated in one embodiment at 13.56 MHz. Of course, other frequencies are possible which produce the plasma generated gas particles. Other frequencies which are useful are between about O cycles (direct current) and microwave frequencies about 1 gigahertz. Preferably, frequencies between about 1 and 20 megahertz are used. More preferably, frequencies between about 5 and 15 megahertz are used. The power supply is connected to the electrodes via an impedance matching network 16. A plasma is produced by applying RF power to the electrodes, and a typical net operating power is 15 Watts. Other power ranges used include, for example, between 1 and 1,000 Watts, preferably between 10 and 100 Watts, and more preferably between 10 and 20 Watts. Thermocouple 14A (lead 14B) is present to monitor the temperature at which the etching is occurring and to monitor the temperature of the sample being etched. Generally, the reaction configuration is at about ambient temperature, except for the source of energy (plasma, UV). Temperatures as high as about 100°C and as low as about 0°C are also useful at the etching site.

Different spacial configurations for the sample to be etched 13 and the non-metallic chemical source 13A are shown in Figure 3(a) to 3(e). The numbers on the left side of Figure 3 describe the general materials. The actual named materials found on the right hand side of the drawing refer to specific materials which were examined. In the specific cases, Figure 3(e) shows the control configuration wherein the KAPTON polymer (polypyromellitimide) to be etched is placed horizontally on a glass stand within the reaction chamber. No sacrificial material or polymer is present.

In Figure 3(a) is shown a vertical downward arrangement of horizontal layers of KAPTON, PYREX, polyethylene and PYREX respectively. When subjected to the reactive gas species, the KAPTON is etched at a faster rate than the control experiment, Figure 3(e).

In Figure 3(b) is shown a vertical downward arrangement of horizontal layers of KAPTON polyethylene, and glass. When subjected to the reactive gas species, the KAPTON etched at a faster rate than the control experiment, Figure 3(e).

In Figure 3(c) is shown a vertical downward sequence of horizontal layers of KAPTON, PYREX (or glass), polyethylene, and PYREX (or glass) wherein the PYREX (or glass) is a short cylinder which has one or more openings 31 so that the plasma generated gas particles are in contact with the lower surface of the polyethylene and top surface of the PYREX. When subjected to the produced reactive gas species, the KAPTON is etched at a faster rate than the control experiment, Figure 3(e).

In Figure 3(d) is shown a vertical downward sequence, horizontal layers of KAPTON and glass. The polyethylene is shown as a thin cylindrical layer on the inside of the reaction vessel. When this configuration is subjected to the plasma generated gas particles, the KAPTON is etched at a faster rate than the control experiment, Figure 3(e).

In Figure 4 is shown the configuration where the standard UV lamp 44 is used to irradiate the reactive gas which reacts with the sacrificial polymer of polyethylene 13A. When this configuration is used to produce the reactive gas species, the KAPTON etches at a faster rate than it does in a similar configuration with polyethylene absent.

In Figure 5 is shown a partial cross-sectional view of the reaction system where the material to be etched 13 is in the shape of a flat circular disk, and the sacrificial polymer 13A is in the shape of a small hollow cylinder which immediately surrounds the material to be etched. When this configuration is subjected to the plasma generated gas particles, the material to be etched etches at a faster rate than it does in control experiment of Figure 3(e).

In Figure 6 is shown in partial cross-sectional view, the reaction system wherein the surface area of the material to be etched 13 is fairly small compared to the surface area of the sacrificial polymer 13A.

In Figure 7 is shown a top cutaway view similar to Figure 6 wherein a single small sample to be etched as a flat disk 13 is placed adjacent to and surrounded by a larger sacrificial polymer 13A. When this arrangement is subjected to the plasma generated gas particles, the material to be etched is etched at a faster rate than is the material to be etched in the control experiment, Figure 3(e).

In Figure 8A is shown a top plan view of the samples to be etched 13 which are surrounded by the sacrificial polymer 13A. This is essentially a top view of Figure 5. When this configuration of Figure 8A is exposed to the plasma generated gas particles, the material to be etched etches at a faster rate than it does in the control experiment, Figure 3(e).

Another embodiment is shown in Figure 8B as a top plan view wherein the material to be etched 13E is separated, but generally adjacent to (about 0.25 to 12.5 cm.) and in close proximity to the sacrificial polymer 13F. When the material to be etched 13E is subjected to the reactive gas species in this arrangement, material 13E etches at a rate faster than it etches relative to the control experiment of Figure 3(e).

In another embodiment, it is also possible to modify Figure 2 so that the non-metallic chemical source 13A is moved from the glass holder into the area of the conveying tube shown as area 22. In one example, sacrificial polymer is moved to the position shown in phantom outline (- - - - -) as 13B. When the material to be etched 13 is subjected to this arrangement, it etches faster than does the sample of the control experiment of Figure 3(e).

In another separate embodiment, it is also possible to modify Figure 2 so the sacrificial polymer 13A is moved from the glass platform into the actual plasma or immediate plasma afterglow as shown in the positions in phantom outline (- - - - - - - -) as sacrificial polymer 13C or 13D respectively. When the material to be etched 13 is subjected to the reactive gas species in this arrangement with sacrificial polymer 13C or 13D, it etches at a rate faster than does the identical sample of the control experiment of Figure 3(e).

The following examples are to be interpreted as illustrative only, and are not to be considered limiting in any way. The materials used are available from various chemical suppliers as listed in Chemical Sources published annually by Directories Publications, Inc., of Columbia, South Carolina. EXAMPLES 1-5

ETCHING OF KAPTON USING POLYETHYLENE

The sample to be etched 13 (Kapton) is placed in the reactor with the sacrificial polymer, a sheet of polyethylene 13A. Other polymers which have a fast etch rate such as polyoctenamer have also been observed to be effective as a sacrificial polymer.

Various configurations of the polyethylene sheet with respect to the sample to be etched are shown in

Figure 3. Following loading, the reactor (Figure 1) is evacuated to a pressure of 0.004 millimeters of Hg or less. Then the valve 17 controlling the oxygen gas inlet is adjusted so that there is a flow of oxygen typically 4 cm³ (STP)/min. The valve 18 leading from the reactor to the pump is adjusted so that the reactor operating pressure is typically about 0.5 millimeters of Hg. Improved etching of polymers has been observed to occur at other reactor pressures in the range of about 0.05 to 1 millimeters of Hg and flow rates from about 0.5 to 10 cm³

(STP)/min.

The results obtained on samples of 7.5 micrometer thick Kapton Type H polymer (from DuPont Co., Wilmington, Delaware) are reported in Table 1 below.

TABLE 1

Etch Rate of KAPTON Type H in the Presence of Polyethylene

Etch Rate (δ) Weight Area Poly¬

Configuration of Kapton H δ/δ (control Polyethylene ethylene Sheet Figure # (μm/hr) Lost (mg/hr) cm²

3(e) (control 0.0075 1.0 none none

3(a) 0.472 63 2.18 2.67

3(b) 0.975 130 4.97 3.01

3(c) 0.682 91 4.54 3.17

3(d) 0.540 73 13.96 26.24

6 0.105 14 4.133 26.24

KAPTON = polypyromellitimide

It is also observed that a film of Shipley Microdeposited S1400-27, a commonly used photoresist, deposited on a glass coverslip and then hard baked according to the manufacturer's instructions, etched 35 times faster when it was substituted for Kapton H in configuration 3(d) than it did when it was substituted for Kapton H in the control configuration.

The specific experimental results are shown below in Table 2.

TABLE 2

Etch Rate of Shipley Photoresist in the Presence of Polyethylene

Etch Rate (δ) Weight Area PolyConfiguration of Photoresist δ/δ (control) Polyethylene ethylene Sheet Figure # (μm/hr) Lost (mg/hr) cm²

3(e)

(control) 0.0118 1.0 None None

3(d) 0.4200 35 10 20

EXAMPLE 6 ETCHING OF KAPTON WITH TEDLAR

TEDLAR and polyethylene are comparable in effectiveness in etching KAPTON sheet. Adjacent samples of polyethylene and KAPTON are exposed in configuration Figure 8B.. Samples of TEDLAR and KAPTON are also exposed using configuration Figure 8B, substituting the TEDLAR for the polyethylene. The etch rate for KAPTON for both cases is found to be ten times the etch rate for KAPTON in the control configuration.

The specific experimental results are shown below in Table 3.

TABLE 3

Etch Rate of KAPTON Type H in the Presence of TEDLAR (TED) or Polyethylene (PE)

Etch Rate (δ) Weight Area

Configuration of Photoresist δ/δ (control) TED or PE TED or PE Sheet Figure # (μm/hr) Lost (mg/hr) cm ²

3(e) (control) 0.0075 1.0 None None

8(a) (TEDLAR) 0.075 10 2.528 10

8(a) (Polyethylene) 0.074 10 1.6 10

TEDLAR = poly(vinyl fluoride)

EXAMPLE 7 ETCHING OF TEFLON

When TEFLON is substituted for KAPTON in the control configuration the etch rate is 0.0015 micrometer/hr. When TEFLON is etched in the configuration of Figure 3(b) it etches at a rate of 0.059 micrometer/hr. This result represents a 39 fold increase in etch rate of TEFLON when the sacrificial polyethylene polymer is present.

The specific experimental results are shown below in Table 4.

TABLE 4

Etch Rate of TEFLON in the Presence of Polyethylene

Etch Rate (δ) Weight Area Poly¬

Configuration of Teflon δ/δ (control) Polyethylene thylene Sheet Figure # (μm/hr) Lost (mg/hr) cm²

3(e) (control) 0.0015 1.0 None None

3(b) 0.059 39 5.695 5

While some embodiments of the invention have been shown and described herein, it will become apparent to those skilled in the art that various modifications and changes can be made in the method to etch photoresists and the like using a reactive gas, a sacrificial polymer in the glow or the afterglow of a plasma glow discharge or subjecting the sacrificial polymer to the products of a direct ultraviolet radiation of a reactive gas without departing from the spirit and scope of the present invention. All such modifications and changes coming within the scope of the appended claims are intended to be covered thereby.

Claims

We claim:

1. A method for etching a sample of a material using a reactive gas species, which method comprises the steps of:

(a) Selecting reaction conditions selected from:

(i) locating a sample of a material to be etched in a gas atmosphere in close proximity of a sacrificial non-metallic chemical source having a very low vapor pressure which is capable of releasing a reactive gas species or a precursor to a reactive gas species, treating a reactive gas with a plasma glow discharge at a location remote from the material to be etched and the non-metallic chemical source, and subjecting the material to be etched at the remote location and the non-metallic chemical source to the plasma generated gas particles of the afterglow of a plasma discharge under conditions effective to release a reactive gas species or a precursor to a reactive gas species which is conveyed to the material to be etched;

(ii) locating a sample to be etched at a remote location and a non-metallic chemical source directly in a plasma discharge with a reactive gas or within the afterglow of a plasma discharge under conditions which release a reactive gas species or a precursor to a reactive gas species, which is conveyed to the material to be etched; or

(iii) locating and subjecting the material to be etched and the non-metallic chemical source to the products obtained from the direct ultraviolet irradiation of the reactive gas under conditions which release the reactive gas species or the precursor to a reactive gas species which is conveyed to the material to be etched; and

(b) etching the material with the released reactive gas species, which chemically reacts with the material to be etched to form volatile species that distill from said material to be etched, thereby causing etching of the material.

2. The method of Claim 1 wherein the reaction conditions of step (a) are the afterglow of the plasma discharge (i).

3. The method of Claim 1 wherein the reaction conditions of step (a) subject only the non-metallic chemical source immediately to the afterglow plasma discharge (ii).

4. The method of Claim 1 wherein the reaction conditions of step (a) subject the reactive gas to direct ultraviolet radiation and subjecting the sacrificial polymer and the material to be etched to the products of UV radiation (iii).

5. The method of Claim 1 wherein the material to be etched is selected from organic materials, inorganic materials or mixtures thereof.

6. The method of Claim 5 wherein the material and non-metallic chemical source are both subjected to the plasma generated gas particles of the afterglow of a plasma glow discharge.

7. The method of Claim 6 wherein the plasma glow discharge is located upstream from the material to be etched with the proviso that the non-metallic chemical source and the material to be etched are contacted by the indirect afterglow of the plasma glow discharge.

8. The method of Claim 7 wherein the reactive gas is selected from fluorine, chlorine, oxygen, nitrogen, nitrous oxide, nitric oxide, nitrogen dioxide, hydrogen or mixtures thereof.

9. The method of Claim 8 wherein the nonmetallic chemical source comprises carbon, hydrogen and oxygen.

10. The method of Claim 7 wherein the reactive gas is selected from oxygen, nitrogen or mixtures thereof.

11. The method of Claim 7 wherein the nonmetallic chemical source comprises carbon and hydrogen.

12. The method of Claim 10 wherein the nonmetallic chemical source comprises carbon, hydrogen and nitrogen.

13. The method of Claim 10 wherein the nonmetallic chemical source comprises carbon, hydrogen and halogen.

14. The method of Claim 1 wherein the vapor pressure of the non-metallic chemical source is about 0.001 millimeters of mercury or lower.

15. The method of Claim 1 wherein: in steps (a) and (b) the material to be etched comprises an organic compound, the non-metallic chemical source is an organic compound having carbon and hydrogen atoms, comprising a vapor pressure of about 0.001 mm of Hg or less, and a plasma glow discharge is generated at a remote location (i).

16. The method of Claim 15 wherein the nonmetallic chemical source is selected from vinyl fluoride polymer, polyethylene, polypropylene, cis-polybutadiene, trans 1,4-polybutadiene, polyacrylonitrile, poly(vinyl chloride), poly(vinyl bromide), cellulose acetate, cellulose butyrate or polystyrene.

17. The method of Claim 15 wherein the reactive gas is oxygen, and the non-metallic chemical source is selected from polyethylene or, poly(vinyl fluoride).

18. The etched article produced by the method of Claim 1.

19. The etched article produced by the method of Claim 6.

20. The etched article produced by the method of Claim 15.

21. An apparatus for etching a sample of material using a reactive gas species, comprising: means for positioning a sample material adjacent a sacrificial non-metallic chemical source; means for generating at least one of a reactive gas and a plasma generated gas particle, said generating means located remotely from said positioning means; means for communicating said at least one of a reactive gas and a plasma generated gas particle with said positioning means such that a reactive gas species or a precursor to a reactive gas species is released.