4.
    发明专利
    未知

    公开(公告)号:DE1278037B

    公开(公告)日:1968-09-19

    申请号:DEJ0024771

    申请日:1963-11-22

    Applicant: IBM

    Abstract: 995,715. Lasers. INTERNATIONAL BUSINESS MACHINES CORPORATION. Nov. 18, 1963 [Nov. 30, 1962], No. 45355/63. Heading H3B. [Also in Division H1] An injection laser has an action region with a cross - sectional shape perpendicular to its smallest dimension, in the form of a regular polygon, all the side faces being optically flat. A cross - section of a rectangular parallelepipedal GaAs crystal, having electrodes at each end and a PN junction in the middle, is shown in Fig. 2. Rays following paths 21, 21a, 21b, meeting crystal surfaces 22, 24, 26 and 28 at 45 degrees are totally reflected. The crystal provides a high Q for such rays and these modes are preferentially established. Once established such modes are maintained at the expense of other modes. The crystal may be surrounded by a material having a refractive index between that of the crystal and air, to modify the internal reflection properties. Other crosssectional geometries shown are triangular and hexagonal. In the latter case (Fig. 5) three modes 46, 48, 50 are possible. Modes 48, 50 may be suppressed by using a material of sufficiently low refractive index, or mode 46 may be suppressed by notching crystal 44 at its vertices. Modes 48 and 50 are optically independent. Light may be coupled out of a crystal by means of a suitably shaped body (Fig. 4, not shown) of refractive index close to that of the crystal, placed within one wavelength of the crystal. The rays may be concentrated into a single beam. Alternatively a protuberance or groove may be provided at a crystal surface for extracting the radiation. The ratio of the refractive index of the crystal to that of the surrounding medium, for optimum mode selection, should be where N is the number of sides of the polygon formed by the cross-section.

    7.
    发明专利
    未知

    公开(公告)号:DE1062821B

    公开(公告)日:1959-08-06

    申请号:DEI0014913

    申请日:1958-05-31

    Abstract: 873,005. Transistors. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 30, 1958 [May 31, 1957], No. 17333/58. Class 37. In a transistor comprising a high amplification factor collector electrode the semiconductor base body decreases in cross-sectional area and conductivity from the emitter to the collector. In the embodiment, Fig. 1, a small areaalloyed junction emitter 9and a surrounding, ring-shaped ohmic base connection 11 are disposed on the large face of a tapering N-type germanium or silicon body 2 and a PN type hook collector 3, 4, on the small face directly opposite the emitter. A base zone resistivity increasing exponentially with distance from the large face of the body is provided by vapour diffusion of donor material into this side of the body. The resistivity gradient gives rise to a drift field and the tapered shape of the base zone to a drift field and a radial focusing field both of which tend to accelerate minority carriers (holes) across the base zone, thereby reducing the transit time and ensuring rapid removal of stored carriers from the base zone. The radial field also tends to restrict emission to the flat central region of the emitter junction over which the injection efficiency is greatest and substantially constant. In its absence a substantial fraction of the emitter current would flow through the edges of the junction where the injection efficiency is lessened on account of the steep resistivity gradient in the base zone at this point. Specification 842,103 is referred to.

    9.
    发明专利
    未知

    公开(公告)号:DE3685842T2

    公开(公告)日:1993-02-04

    申请号:DE3685842

    申请日:1986-04-11

    Applicant: IBM

    Abstract: An ohmic contact is formed to a device region in the surface of an extrinsic conductivity type group III-V semiconductor crystal (1) by providing a layer (3) of an amphoteric dopant on the surface of the crystal and providing in that layer, at the desired location of the ohmic contact, a localised quantity of atoms of the element of the crystal which is capable of imparting with the amphoteric dopant the aforesaid extrinsic conductivity type, and heating the structure to diffuse atoms from the layer into the surface of the crystal to form the ohmic contact. A layer of Si on GaAs upon heating normally forms a rectifying contact. If a region of the Si layer contains As atoms, an ohmic contact is formed on heating.

    10.
    发明专利
    未知

    公开(公告)号:DE2325555A1

    公开(公告)日:1973-12-20

    申请号:DE2325555

    申请日:1973-05-19

    Applicant: IBM

    Abstract: 1416644 Non-volatile memory devices INTERNATIONAL BUSINESS MACHINE CORP 15 March 1973 [5 June 1972] 12472/73 Heading H1K A multi-state switch with non-volatile memory comprises a substrate of a refractory metal, e.g. tungsten, molybdenum, niobium or tantalum, a film of aluminium nitride formed thereon by sputtering after outgassing the substrate for at least 10 minutes at 350- 1500‹ C. at a pressure of from 2 Î 10 -7 to 2 Î 10 -8 Torr and an electrode on the film. Typically when using a 111 orientated mono- or polycrystalline tungsten or molybdenum substrate a series of presputtering steps in argon or nitrogen is performed prior to reactively sputtering aluminium in pure nitrogen at 1100‹ C. to form a film 0À2-10 Á thick. The film is electroded by alloying P- or N-type silicon to it at 1420-1800‹ C., or aluminium-silicon at above 576‹ C., or by sputtering, evaporating, or alloying on aluminium at 660-1800‹ C. A forming voltage of either polarity is then applied to realisethe switching characteristic. Switching from a high to a low impedance condition occurs above a threshold voltage with the electrode positive and reversion takes place when a threshold current of opposite polarity is exceeded. The ratio high/low impedance may be as high as 10,000 : 1 at very low switching frequencies but falls to about 20 : 1 at 100 kc./s. At a given frequency the values of the high and low impedances and the switching thresholds are determined by the amplitude of the voltages applied but switching is substantially independent of temperature in the range 4-500‹ K. The device finds use as a computer memory element,' high speed pulse or harmonic generator or electrically resettable circuit breaker.

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