Tummers v. Kleimack

• Decision Date: 24 February 1972
• Docket Number: Patent Appeal No. 8603.
• Citation: 59 CCPA 846,455 F.2d 566
• Parties: Leonard J. TUMMERS, Appellant, v. Joseph J. KLEIMACK et al., Appellees.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

59 CCPA 846, 455 F.2d 566 (1972)

Leonard J. TUMMERS, Appellant, v. Joseph J. KLEIMACK et al., Appellees.

Patent Appeal No. 8603.

United States Court of Customs and Patent Appeals.

February 24, 1972.

Jack Oisher, Briarcliff Manor, N. Y., attorney of record, for appellant.

David I. Caplan, Arthur J. Torsiglieri, Murray Hill, N. J., attorneys of record, for appellees.

Before RICH, ALMOND, BALDWIN, and LANE, Judges, and RAO, Judge, United States Customs Court, sitting by designation.

ALMOND, Judge.

This is an appeal from the decision of the Patent Office Board of Patent Interferences, adhered to on reconsideration, awarding priority to appellees, Joseph J. Kleimack, Howard H. Loar, and Henry C. Theuerer (hereinafter Kleimack).

Appellant, Tummers, is involved on application serial No. 349,709 filed March 5, 1964 as a division of application serial No. 84,923,¹ filed January 25, 1961, and accorded the benefit of a January 29, 1960 foreign priority date.² The Tummers' application is assigned to North American Philips Co., Inc. The sole count in the interference was copied from the Kleimack patent, No. 3,165,811, issued January 19, 1965 on an application filed June 10, 1960. The Kleimack patent is assigned to Bell Telephone Laboratories, Inc.

The invention in issue relates to a method of making a diffused junction transistor. It is best understood from the following analysis of the count, which was provided as an appendix to appellees' brief:

Drawing of the Device Formed by the Process Described in the Count of this Interference After Each Step Thereof (Assuming an NPN Transistor)

1. The method of making a junction transistor comprising the steps of

forming by vapor deposition on a surface portion of a semiconductive body an epitaxial layer of higher specific resistivity than the specific resistivity of said surface portion,

diffusing into a surface portion of the epitaxial layer a conductivity-type impurity for forming in said layer a first region of a conductivity type opposite that of said surface portion of said semiconductive body, while leaving a high specific resistivity portion of said epitaxial layer between said first region and the original surface portion of said body, and

introducing into a limited surface portion of the first region a conductivity-type impurity of the type opposite that diffused into the first region for forming within said first region a second region of the opposite conductivity type, the second region serving as the emitter region, the first region serving as the base region, and the semiconductive body including the collector region of the junction transistor.

The primary issue in this case centers around the first step of the count which recites the vapor deposition of an epitaxial layer of high resistance on a substrate. Both parties agree that "epitaxial" means at least that it is (a) a single crystal with (b) a crystal orientation determined by that of the substrate. The evidence also supports the board's finding that "epitaxial" implies that the substrate for the layer is also a single crystal since single crystal layers do not ordinarily grow on polycrystalline substrates.

After the interference was declared, Kleimack moved to dissolve the interference on the grounds that Tummers could not make the count, (1) because the first step of the count is not disclosed by Tummers and (2) because the Tummers' disclosure is not enabling. In the alternative, Kleimack concurrently moved for leave to take testimony on these issues should the motion to dissolve be denied. The primary examiner denied the motion to dissolve, but the board granted the motion for leave to take testimony. Both parties took testimony and submitted exhibits. After briefs were filed and oral arguments heard, the board awarded priority to Kleimack on the ground that Tummers was not entitled to make the count. This decision was adhered to on reconsideration.

The only issue before us is whether Tummers' application supports the first step of the count. More particularly, the issue is whether the disclosure of a vapor-deposited epitaxial layer is inherent in the Tummers' disclosure which does not explicitly mention epitaxial layers, but discloses vapor depositing a germanium layer on a silicon layer in a "known manner."

There is a considerable amount of evidence in the record pertaining to the state of the art as of January 1960 (the filing date of Tummers' Dutch application), and, contrary to appellant's arguments, we think the sufficiency of the Tummers' disclosure must be determined as of that date.³ We will not attempt to set forth all that the evidence shows in that regard. However, in general we think it fair to say that vapor deposition of epitaxial layers in homoepitaxial growth, for example silicon on silicon, was well known in 1960. In fact, the testimony indicates that all commercial bipolar transistors were homoepitaxy and that such transistors were widely used in 1960. Heteroepitaxial growth, for example germanium on silicon, on the other hand, was difficult, if not impossible, to achieve in 1960 and it certainly was not commercially feasible. There is a four percent mismatch in the lattice constants (size of a unit crystal cell) between germanium and silicon and, at least partially for that reason, all reported efforts to grow epitaxial germanium layers on silicon resulted in the formation of microscopic islands of epitaxial growth or unoriented polycrystalline aggregates.

The board, after making findings of fact much more thorough than the brief summary above, found that Tummers had not sustained his burden of showing that his disclosure inherently supports the count and, therefore, held that he could not make the count. The board found that the processes of depositing a germanium layer on a silicon substrate available to those skilled in the art in 1960 would not inevitably produce an epitaxial layer as required by the count, but could result in polycrystalline growth or result in the formation of unusable germanium islands.

Appellant takes exception to every aspect of the board's decision, but in the main contends that the board erred in...