T 1905/10 28-05-2014

Reasons for the Decision

1. Sufficiency of disclosure (Article 83 EPC)

Main request

1.1 The Opposition Division in its impugned decision concluded that the respondent's experiments (see point II above) are within the wording of claim 1 of the patent as granted, which contains no limitations concerning the apparatus, temperature and gas flows. It considered that the examples only disclose HCl concentrations of 4.6% and 7.5% HCl. It held that the experiments unambiguously demonstrate that when carrying out the invention of the patent in suit with a deposition process gas comprising 30% HCl no TiCN deposition takes place on any of the substrates. It therefore concluded that "the skilled person is not able to obtain substantially all embodiments falling within the ambit of claim 1" (see point 3.2 of the reasons).

1.2 Since the appellant failed to show that the impugned decision is wrong the Board reaches the same conclusion with respect to Article 83 EPC for the following reasons.

1.3 First of all, the process of claim 1 of the patent as granted - comprising the two steps a) and b) - does not require any specific CVD reactor, or specific flow rates, or specific temperatures but only requires introducing into the heated reaction chamber a deposition process gas comprising from 1-30% hydrogen halide and predetermined amounts of a carbon/nitrogen source, a metal-halogen compound, and hydrogen, so that a carbonitride-containing coating deposits on the substrate surface (see point VIII above).

Furthermore, the patent in suit explicitly states in paragraph [0059] with respect to the CVD reactor type or its design "Although the foregoing examples were conducted in a conventional reaction vessel chamber of the design described above, it is to be understood that the present invention may be practiced in any design of reaction chamber known to those skilled in the art to be adaptable for use with conventional MT CVD".

Consequently, the appellant's arguments that the non-deposition of TiCN at a concentration of 30% HCl according to the opponent's experiments would be caused by the use of another CVD reactor having a different geometry and size that inevitably results in different gas flows in the trays as compared to the CVD reactor described in the patent in suit (see paragraph [0033]) cannot hold. In this context the Board also considers that it cannot be expected that the respondent has a reactor identical with the one described in the patent in suit for carrying out comparative experiments. Furthermore, the gas flows as given in test B of the patent in suit have been re-calculated by the respondent to suit the reactor size of the Bernex 200 reactor underlying its experiments.

1.3.1 Claim 1 of the patent as granted according to the main request is also not restricted to the deposition of TiCN which is the only compound deposited according to the examples 1 and 3-6 corresponding to the tests A and C-G and their reaction conditions (see patent in suit, table 1).

The deposition gas composition according to example A thus contained (in %) 4.6 HCl, 0.4 CH3CN, 1.3 TiCl4, 77.1 H2 and 16.5 N2. The deposition gas composition of tests D, E and G is identical. The deposition gas composition according to example C contained 7.5 HCl, 0.7 CH3CN, 2.1 TiCl4, 62.8 H2 and 26.9 N2, while that of example F contained (in %) 4.6 HCl, 0.3 CH3CN, 0.9 TiCl4, 77.6 H2 and 16.6 N2 (see table 1).

The deposition gas compositions (i.e. the concentrations of the components HCl, CH3CN, TiCl4, H2 and N2) and the reaction conditions (i.e. a reaction temperature of 870°C or of 830°C/870°C; and a reaction pressure of 120 Torr) of these tests A and C-G, made with either 4.6% HCl (tests A and D-G) or 7.5% HCl (example C), are within the two composition ranges mentioned in paragraph [0023] and the corresponding parameter ranges mentioned in paragraphs [0024] and [0025] of the patent in suit, which correspond to the preferred ranges of the claimed MT CVD process specified in its dependent claims 21 and 23, namely from 2.3 to 20% HCl, from 0.3 to 0.7% CH3CN, from 0.9 to 2.1% TiCl4, from 50 to 85% H2, and from 10 to 30% N2. Further, a reaction temperature in the range of 830 to 880°C and a reaction pressure of 40 to 120 Torr were used.

1.3.2 Therefore the Board is satisfied that the patent in suit discloses at least one way for carrying out - a part of - the invention, namely the deposition of TiCN from a deposition gas comprising 4.6% HCl and 7.5% HCl besides CH3CN, TiCl4, H2 and N2, which is supported by the five tests A and C-G according to the examples 1 and 3-6.

This conclusion is also supported by the respondent's experiments at varying HCl concentrations in the deposition gas composition of (in %) 7, 10, 15, and 20 HCl, respectively, which all resulted in a deposition of TiCN on the substrates.

1.3.3 However, according to the case law the disclosure of one way of performing an invention is sufficient only - as correctly considered by the Opposition Division in its decision - if it allows the invention to be performed in the whole range claimed and without undue burden. Sufficiency of disclosure thus presupposes that the skilled person is able to obtain substantially all embodiments falling within the ambit of the claims (see Case Law of the Boards of Appeal, 7**(th) edition 2013, sections II.C.4.2 to II.C.4.4).

The mere statement "disclosing one way of performing the invention suffices for compliance with Article 83 EPC" is an incorrect simplification of the jurisprudence of the Boards of Appeal.

The appellant's argument that the relevant jurisprudence would address only functional features cannot hold since the above elaborated principle applies to any invention irrespective of the way in which it is defined (see Case Law of the Boards of Appeal, 7**(th) edition 2013, II.C.4.4; see e.g. T 369/05, not published in OJ EPO, point 3.3 of the reasons).

Further, the wording of feature b) of claim 1 of the patent as granted "introducing into said reaction chamber a deposition gas ... so that a carbonitride-containing coating deposits on said surface of said at least one substrate" (see point VIII above) defines a result to be achieved, i.e. feature b) of claim 1 represents a functional feature as well.

Furthermore, the appellant's argument that the end value of 30% HCl would not be technically relevant is irrelevant taking account of the established jurisprudence which requires that the invention can be performed in the whole range claimed.

1.3.4 This aforementioned condition, however, is not fulfilled by the patent in suit - as proven by the respondent's experiment at 30% HCl - for the following reasons.

1.4 Example B of the patent in suit has a deposition gas composition very similar to those of the examples A and D-G due to its amounts (in %) of 0.5 CH3CN, 1.4 TiCl4, 80.9 H2 and 17.3 N2. It is stated to represent an example comparative to the invention of the patent in suit of a conventional MT CVD deposition without any addition of HCl to the deposition gas composition.

1.4.1 The Board considers that the person skilled in the art, when aiming to perform the claimed invention of the patent in suit in its broadest scope, i.e. to perform the claimed MT CVD process with a deposition gas composition comprising from 1 to 30% hydrogen halide as specified in claim 1 of the main request, would - since the description and particularly the detailed description is silent in this respect - either start from the examples disclosed in the patent in suit (i.e. tests A and C-G), or alternatively, would start from the (true) comparative example that is only distinguished from the inventive examples by the omission of a single feature, namely the non-presence of a hydrogen halide. Test B represents such a comparative example. Both are equally feasible approaches.

1.4.2 Thus the skilled person when starting from the examples A and C-G is expected to either increase the amount of HCl in their deposition gas compositions up to the maximum value of 30% HCl or, when starting from the comparative example B, he is expected to start adding HCl to the deposition gas composition of example B up to the maximum value of 30% HCl as done by the respondent in its experiments. Furthermore, the person skilled in the art is expected to apply the reaction temperatures and reaction pressures of the examples and to use a CVD reactor similar to the one described in the context of these examples.

1.4.3 Since the description of the patent in suit is silent about how a compensation for an increasing HCl content in the deposition gas composition has to be achieved, e.g. whether the concentration of H2 or N2 has to be reduced when the amount of HCl is to be increased, the skilled person could select any of the two. In case that HCl is added to a deposition gas composition without any nitrogen then it will automatically be the H2 which will be replaced.

1.4.4 In this context it is likewise clear to the skilled person that

a) considering the chemistry of the CVD deposition of TiCN due to the underlying sum reaction:

TiCl4 + CH3CN + 2 ½ H2 + N2 ? TiCN + 4 HCl + CH4 + N2

H2 is a reactant which contributes to HCl formation and the reduction of the carbon/nitrogen source whereas N2 is an inert gas not taking part in the deposition reaction; and

b) taking account of the very large molar excess of H2 (based on the assumption that the molar ratios of the gaseous reactants correspond more or less to their volume proportions, i.e. vol.%, which assumption is only fully correct for ideal gases but sufficient in the context of this estimation) compared to the low molar amount of H2 necessary for the aforementioned deposition reaction most of the H2 acts (likewise as the N2) as carrier gas only.

This conclusion is also plausible in view of the fact that a (lowered) H2 concentration of the thereby resulting deposition gas compositions according to the respondent's experiments starting from the composition of test B (which contained 80.9% H2) - i.e. after a compensation for an increasing HCl amount of (in %) 7, 10, 15, 20, 25, and 30 HCl the compensated H2 concentration is 73.9, 70.9, 65.9, 60.9, and 50.9, respectively - is still within the preferred range of about 40% to about 98% H2 mentioned in paragraph [0023] of the patent in suit.

1.4.5 Taking account of the respondent's plausible explanations concerning the influence of a different reactor geometry and adapted gas flow on the deposition of the carbonitride compound in a CVD reactor, namely where the deposition of TiCN starts, the appellant's argument that the respondent had the intention to obtain a failure at high HCl concentrations are, without any evidence in support thereof, considered to be mere allegations.

1.4.6 Consequently, from the Board's point of view the respondent's experiments at 30% HCl starting from example B cannot be objected to and the appellant's corresponding arguments to the contrary cannot hold. As discussed in points 1.4.1 and 1.4.2 above, there exists no plausible reason for the person skilled in the art, particularly in view of the missing information in the patent in suit concerning any compensation for the increase in the HCl concentration in the deposition gas composition, not to start from the deposition gas composition of test B of the patent in suit and then to increase the HCl concentration up to the claimed maximum amount of 30% HCl.

1.4.7 The appellant's arguments that the burden of proof lies with the respondent to establish that the tests have been performed accurately cannot hold.

This is due to the fact that the patent in suit has been revoked by the impugned decision and that the respondent - in accordance with the established case law (see e.g. T 63/06, not published in OJ EPO, points 3 to 3.3.4 of the reasons) - on the basis of its comparative experiment with a deposition gas composition comprising 30% HCl has shown that no TiCN was deposited on the substrates in the trays of the CVD reactor, i.e. that the common general knowledge does not enable the person skilled in the art to put the functional feature of the deposition of a carbonitride-containing coating on the substrate surface at 30% HCl into practice. These two facts shift the burden of proof to the appellant. The appellant has not, however, submitted sufficient evidence to show the opposite and to discharge its burden of proof (compare point 1.5 below).

1.5 In order to rebut the respondent's experiments the appellant submitted the counter-experiments D17 (tests 1 and 2 with 20.34% and 30.8% HCl) and D18 (with 20.04% HCl). The tests of D17 were conducted in a TC Kencoat furnace (#2) and an Orwell Kencoat furnace (#44) - which are stated to correspond to that of figure 1 of the patent in suit - while the test of D18 was carried out in said TC Kencoat furnace #2 but with a modified gas inlet.

1.5.1 However, neither the tests of D17 nor those of D18 have been made in agreement with the deposition gas compositions and reaction conditions of the examples (tests A and C-G) according to Tables 1 and 2 of the patent in suit, let alone those starting from test B used in the experiments of the opponent (compare point 1.4 above):

- the concentration of 30.8% HCl according to test 2 of D17 lies outside the range of 1 to 30% HCl specified in claim 1 of the main request;

- the tests of D17 and D18 were performed at a different reaction pressure (i.e. 76 Torr compared to 120 Torr and 90 Torr specified for test A-D and G, and tests E and F, respectively; see Table 2 of the patent in suit);

- different deposition times were used (tests 1 and 2 of D17 used 100 and 75 minutes, respectively compared to 180 minutes of D18 and tests A-G);

- different (D18) or unspecified flow rates (D17) were used;

- the deposition gas composition of tests 1 and 2 of D17 did not comprise any N2 at all while that of D18 contained (in %) 18.7 N2 compared to 16.5, 17.3, 26.9, 16.5, 16.5, 16.6 and 16.5 N2 according to tests A-G, respectively;

- tests 1 and 2 of D17 used (in %) 3.1 and 2.89 TiCl4 while D18 used 1.88 TiCl4 compared to 0.9-2.1 according to tests A-G; and 1.3 and 1.64 CH3CN (tests 1 and 2 of D17) and 0.61 CH3CN (D18) compared to 0.3-0.7 CH3CN according to tests A-G; and

- higher temperatures of 880-900°C and 900°C (tests 1 and 2 of D17) and 880-900°C (D18) were used instead of 870°C or 830/870°C according to tests A-C and G, and D and E, respectively.

1.5.2 Hence, these tests of D17 and D18 - which were performed with different deposition gas compositions and process parameters than the ones used in the respondent's experiments - are not suitable to rebut the comparative tests made by the respondent and particularly not the test with no TiCN deposition at 30% HCl.

Therefore the Board considers that the appellant has not produced or submitted counter-experiments which would prove that with the reaction conditions and a modified deposition gas composition starting from test B as used in the experiments of the respondent, i.e. comprising 30% HCl, it would be possible to produce a TiCN coating on the substrates at all, let alone with thickness values in the range as given in table 3 of the patent in suit.

1.6 According to the established case law the disclosure of an invention must be reproducible without undue burden but allows for an occasional failure which according to the jurisprudence could be established if only few attempts are required to transform failure into success, provided that these attempts are kept within reasonable bounds and do not require inventive step (see Case Law of the Boards of Appeal, 7**(th) edition 2013, section II.C.5.6.2; T 931/91, not published in OJ EPO).

The Board considers that, contrary to the appellant's arguments, the experiment of test 2 of D17 does not prove an occasional failure at 30% HCl for the following reasons.

1.6.1 Firstly, it is apparent from the tendency of the decreasing average deposition thickness of TiCN in the diagram of the average deposition thicknesses based on the respondent's experiments (see respondent's letter of 22 April 2014, page 10, diagram) that no deposition would occur at 30% HCl since the dotted trend-line of this average deposition thickness already at about 27% HCl reaches the value zero. Consequently, it is clear that there is no occasional failure at a single HCl concentration point.

When asked by the Board at the oral proceedings, the appellant did not make any comment with respect to the trend shown in this diagram but only stated that the person skilled in the art would not start from an example (i.e. like example B) not containing HCl.

1.6.2 Secondly, the conditions and parameters according to said test 2 of D17 have been modified considerably as compared to those of the respondent's example at 30% HCl and those of the examples of the patent in suit (compare points 1.3.1, 1.4 and 1.5.1 above) and are outside the preferred ranges of the patent in suit.

When asked by the Board at the oral proceedings that at least 6 parameters have been modified according to test 2 of D17 as compared to the respondent's experiment with 30% HCl based on test B of the patent in suit, the appellant stated that not much more can be said in this respect other than that the experiments of D17 were made in a commercial reactor and not in a laboratory scale one. This answer, however, does not explain why these at least six parameters (i.e. the reaction temperature, the reaction pressure, and the concentrations of CH3CN, TiCl4,H2 and N2) have been modified and particularly, why they have been modified in this specific manner.

The Board considers that the skilled person is not in a position to complete the missing information - the specification of the patent in suit is silent with respect to any compensation for an increasing amount of HCl, let alone with respect to an adaption of the concentrations of the components CH3CN and TiCl4 for the deposition of TiCN at higher HCl concentrations or how these concentrations should be adapted in combination with any other process parameters - concerning the compensation of any changes of the HCl concentration in the range of 1 to 30% HCl by using his common general knowledge. He therefore has to carry out a number of experiments based on the disclosure of the examples which amount to a small research program (see T 339/05; not published in OJ EPO, point 3.6 of the reasons).

The appellant's argument that the skilled person would be taught by the examples of the patent in suit that the concentrations of CH3CN and TiCl4 should be increased for high(er) HCl concentrations cannot hold. The majority of these examples, i.e. tests A and D-G, uses lower concentrations of CH3CN and TiCl4 than the comparative test B (without addition of HCl) at a comparable total gas flow while test C although using somewhat higher concentrations of CH3CN and TiCl4, used a much lower total gas flow (see tables 1 and 2). Furthermore, there is no suggestion at all to the person skilled in the art in the patent in suit to omit the N2 - which is comprised in all the compositions of the tests A-G -from the deposition gas composition.

1.7 Therefore, the invention of claim 1 of the patent as granted according to the main request, in the light of the description and the figures of the patent in suit, does not comply with Article 83 EPC. The main request is therefore not allowable.

Auxiliary request 1

1.8 Process claim 1 of auxiliary request 1 has been restricted to a deposition gas composition containing from 2.3 to 20% HCl, from 0.3 to 0.7% CH3CN, from 0.9 to 2.1% TiCl4, from 10 to 30% N2, and from 50 to 85% H2 and to a resulting coating of TiCN (see point IX above).

1.8.1 Besides the five examples of the patent in suit executed with a coating of TiCN from deposition gas compositions comprising 4.6 or 7.5% HCl (see points 1.3.1 and 1.3.2 above) it is also evident from the diagram of the average deposition thicknesses based on the respondent's experiments that a coating of TiCN is deposited within the concentration range of 7-20% HCl (see respondent's letter of 22 April 2014, page 10, diagram).

1.8.2 The Board remarks that the respondent has not raised any further Article 83 EPC objection with respect to the invention of claim 1 of auxiliary request 1. Taking account of the conclusion in point 1.8.1 above the Board considers that the invention of claim 1 of auxiliary request 1 complies with Article 83 EPC.

2. Admissibility of amendments (Articles 123(2) and (3) EPC)

Auxiliary request 1

2.1 Claim 1 of auxiliary request 1 is based on a combination of the claims 1, 15 and 21 of the patent as granted which are based on claims 15 and 21 of the application as originally filed (corresponding to the published WO-A-00/52224). By incorporating the additional features relating to the further components of the deposition process gas composition and their concentration ranges and by specifying that a coating of TiCN is deposited (see point IX above) the scope of the subject-matter of claim 1 of auxiliary request 1 has been restricted compared to that of claim 1 of the patent as granted.

2.1.1 Claims 2 to 9 of auxiliary request 1 are based on the following claims of the patent as granted: claim 22; claim 23; a combination of claims 1, 8, 26 and 32; claims 37 and 43; claim 33; claims 34 and 45; claims 6, 13, 19, 24, 30, 35, 41 and 46; and claims 7, 14, 20, 25, 31, 36, 42 and 47; respectively. Claims 2 to 9 of auxiliary request 1 have also their basis in the following claims of the application as originally filed (corresponding to the published WO-A-00/52224): claim 22; claim 23; claims 26 and 32; claims 37 and 43; claim 33; claims 33 and 45; claims 24, 30, 35, 41 and 46; and claims 25, 31, 36, 42 and 47, respectively.

2.1.2 Consequently, the amendments made to the claims 1 to 9 of auxiliary request 1 do not contravene Article 123(2) and (3) EPC. Auxiliary request 1 is therefore considered not to be formally objectionable except for a typing error in claim 9 "The process described in claims 8" which correctly should read "The process described in claim 8".

3. Remittal to the department of first instance (Article 111(1) EPC)

Since the Opposition Division has not yet dealt with the opposition grounds under Article 100(a) EPC, i.e. lack of novelty and lack of inventive step, the Board, in exercising its discretion provided under Article 111(1) EPC, decides to remit the case to the department of first instance for further prosecution.