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"Technical Problem" as a Contributing Factor to Inventiveness Assessment

When determining whether a technology seeking protection in a patent application possesses inventiveness, an examiner usually needs to make several assessments, for example, regarding technical improvement, features and enlightenment, etc. This article discusses another important contributing factor in inventiveness assessment - the technical problem actually solved by the claimed invention.

 

The principle of inventiveness assessment, pursuant to the Guidelines for Patent Examination (“the Guidelines”), is that when evaluating whether or not an invention involves an inventive step, the examiner shall consider not only the technical solution itself, but also the technical field to which the invention pertains, the technical problem solved, and the technical effects produced by the invention, and treat the invention as a whole.

 

The Guidelines provide a "three-step method" for inventiveness assessment, which consists of a series of determinations in a specific order: (1) determining the closest prior art; (2) determining the distinguishing technical features of invention and the technical problem actually solved by the invention; (3) determining whether the claimed invention is obvious to a person skilled in the art.

 

Regarding step (1), the Guidelines further stipulate that “the closest prior art may, for example, be an existing technology in the same technical field as the claimed invention, whose technical problem actually solved, technical effects, or intended use are the closest to the claimed invention, and/or which has disclosed the greatest number of technical features of the claimed invention; or be an existing technology which, despite being in a different technical field from the claimed invention, is capable of performing the function of the invention and has disclosed the greatest number of technical features of the invention.”

 

Regarding step (3), the Guidelines require assessments on whether the claimed invention is obvious to a person skilled in the art in view of the closest prior art and the technical problem actually solved by the invention.

 

From these requirements, it can be seen that no matter judging by the general principles or the specific rules, from determination of the closest prior art to the assessment of obviousness, "technical problem" is always a contributing factor to the inventiveness assessment.

 

In practice, it is often the case that the "three-step method" is over-rigidly applied. Specifically, an examiner would sometimes jump to the conclusion that the claimed invention does not possess inventiveness by following a simplistic reasoning: comparing the technical features of the claimed invention and the prior art references, determining the technical problem, pointing out the distinguishing feature, and asserting it is common knowledge or obvious. However, in essence, making the assertion requires a comprehensive analysis on the whole schemes of the claimed invention and the closest prior art, in terms of the technical fields, problems actually solved and technical effects, etc., rather than merely judging whether the distinguishing technical feature has been disclosed in the reference documents or whether it is common knowledge.

 

Case
One of our recent responses to an inventiveness rejection gave an example on how “technical problem” should be addressed in the assessment. In short, we compared the technical problems and the technical schemes of the claimed invention and the prior art reference, pivoting on the different intentions behind the problem-solving approaches, and argued that the reference had not provided technical enlightenment to solving the technical problem brought up by the claimed invention. The reexamination panel accepted our arguments and ultimately revoked the inventiveness rejection.

 

In the inventiveness rejection, the distinguishing technical features of Claim 1 over Reference 1 were identified as: the substrate is poly-silicon; spacing between each select gate wordline and a dummy wordline is adjustable correspondingly to select-gate to core cell wordlines requirements. Based on the above distinguishing technical features, it can be determined that the technical problems actually solved by the claim are: forming a pattern on the poly-silicon substrate, and preventing accidental overlay and crosstalk with the select-gate on a core cell wordline. The examiner thought it was common knowledge in the art to use poly-silicon to prepare the substrate or the gate of a semiconductor device. In addition, it was a basic requirement in the field to prevent the crosstalk and overlay between the select-gate and the core cell wordlines. Therefore, in order to align the patterns and prevent overlay and crosstalk, a person skilled in the art could readily use the method for forming patterns having various widths simultaneously to make an adjustment, and thus obtained the technical scheme of the invention.

 

We couldn’t agree with this understanding. We noted that the background section of the present application wrote: the spacing between a select-gate wordline and a nearest core cell wordline may vary and this inconsistency in select-gate wordline placement leads to a number of well-known difficulties in semiconductor device operation. According to Reference 1, its method, however, is to overcome problems of misalignment that may occur between wordlines having various widths while the interval/spacing between the patterns is uniform. That is, Reference 1 does not address the problem of varied spacing between the select-gate wordline and the nearest core cell wordline, which is what the claimed invention tries to solve.

 

Before the disclosure of the present application, a person skilled in the art did not know the technical scheme of the claimed invention, even though they might have seen Reference 1. The questions for assessing the inventiveness of the claimed invention should be: whether a person skilled in the art, having knowledge of Reference 1, faces the technical problems solved by the present application; and whether the existing technologies would give the technical enlightenment of applying the distinguishing technical features of the claimed invention to solve the technical problems. Specifically to this case, Reference 1 only realizes pattern alignment for uniform spacing between different wordlines and does not mention that for different spacing. It gives no technical enlightenment to the technical problems solved by the present application. A person skilled in the art would not have the motivation to improve the technical scheme of Reference 1 to address the technical problems solved by the present application.

 

Therefore, in the responses, we wrote: regarding determination of the closest prior art, prioritized consideration should be given to the technical problem actually solved, the technical effects, or the intended use, of the inventions, rather than the number of similar technical features disclosed. Reference 1 does not solve the same problem nor brings the same technical effects as the claimed invention does. It should not be deemed as the closest prior art of the present application.

 

We further pointed out that Reference 1 provides the technical schemes merely to the alignment of different wordlines with uniform spacing although the wordlines have different widths. It does not give any technical enlightenment on how to avoid the interference or overlap between the select-gate wordlines and the core cell wordlines. Even when the size of the semiconductor features is gradually decreasing and a person skilled in the art has been trying to avoid interference and overlap between the wordlines, it is not easy for them to come up with the idea of setting the dummy wordlines between the select-gate wordlines and the core cell wordlines and adjusting the space between the select-gate wordlines and the dummy wordlines according to the target spacing between the select-gate wordlines and the core cell wordlines, in order to avoid interference and overlap between the select-gate wordlines and the core cell wordlines. Such a solution requires changing the setting of the mask of the etching process of the doubling patterning, so that the mask pattern can leave dummy wordlines between the select gate wordlines and the core cell wordlines. It was clearly not obvious.

 

As mentioned earlier, the collegial panel, after receiving and deliberating over the above-mentioned opinions, decided to revoke the inventiveness rejection.

 

Summary
The above handling reveals that the technical problem actually solved by the claimed invention should be identified before determining whether a particular technical enlightenment exists in prior arts, and the latter should be considered by reviewing the technical points as a whole.

 

Apparently, a technical problem can be solved only after it has been identified. For a person skilled in the art, the process of solving the technical problem would involve answering the question - whether the prior art gives any technical enlightenment of applying the distinguishing technical features to the closest prior art to solve the technical problem. In other words, the first step of the determination should be to find out whether the technical problem actually solved by the claimed invention has been identified in the field. If not, it means that a person skilled in the art is not aware of the technical problem before the present application, and moreover it would be illogical for them to apply any prior art and seek any technical enlightenment to solve the technical problem.

 

The consideration surrounding technical problem of a claimed invention functions as an indispensable step in inventiveness assessment. When determining whether a technical scheme or claim possesses inventiveness, one needs to understand and capture the role of identifying technical problem and fairly address the three-step method in order to render tenable opinions. As a patent attorney, that would be one of the most important skills that help protect the interest of clients.

 

This article was first published on IPLink-Asia.

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