DD250247A3 - Method for improving the ohmic contact behavior of chip-bonded semiconductor bodies - Google Patents

Abstract

The aim and object of the invention is to provide a method to increase the yield of chip-bonded semiconductor bodies by improving the ohmic contact behavior. This is achieved according to the invention by means of a targeted selective single or multiple electrical impulse stress, wherein the stress is adjusted to the individual component type by pulse height, pulse duty factor and pulse duration. After applying the method, the treated semiconductor devices have stable characteristic curves ICf (UCE).

Description

Before the final measurement, the phototransitors were pretreated by impulse stress

! Collector emitter = 500 ITiA, duty cycle = 1: 1 000,

Pulse duration = 10 ~ ³ s, resp.

iCoector emitter = 700 ITiA, pulse duration = 10 ^-4 s, single pulse

To achieve the highest possible current pulses, without exceeding the limit load capacity of the components, the electrical pulse train or the electrical pulse was directed so that the emitter of the transistors was positively poled.

Properties of the phototransistors without treatment according to the invention:

High saturation voltage and sometimes strong instability of the saturation voltage UcEsat · At a light current of Ic = 200 μΑ (E = 1000Ix), saturation voltages of U _C Esat = 0.1 ... 2.5V were measured.

Properties of the phototransistors with treatment according to the invention:

Stable characteristic curve l _c = f (U _C E) / where the saturation voltages were in the range of U _C Esat = 0.1 ... 0.2V.

Characteristic characteristic curves with and without application of the method according to the invention are shown in the attached figure.

Claims (4)

-1- 250 24 claim: 1. A method for improving the ohmic contact behavior of chip-bonded semiconductor body, in particular radiation receiver, characterized in that the bonded contact system is loaded by a directed electrical pulse in the region of its limit stress 2. The method according to item 1, characterized in that a single pulse is applied. 3. The method according to item 1, characterized in that an electrical pulse train is applied. 4. The method according to item 1 to 3, characterized in that the electrical pulse is so directed is1 that a positive potential is applied to transistors at the emitter. For this 1 page drawing Field of application of the invention The invention relates to a method for improving the ohmic contact behavior of chip-bonded semiconductor bodies, in which the standard chip bonding technology with conductive adhesive is used. The process according to the invention can be used as a permanent component of the production process or as a subsequent substep to increase the yield Characteristic of the known technical solutions For the manufacture of semiconductor devices, it is necessary to secure the bare semiconductor chips on suitable carrier materials so that the compound gives the chips a sufficient strength even under extreme conditions, and guarantees sufficient heat dissipation and a low contact resistance. In the case of optoelectronic components, in addition, the electro-optical properties such as, for example, the beam strength in transmitter components or the photosensitivity in receiver components, but also the degradation behavior must not be adversely affected. While semiconductor chips have traditionally been conductively attached to the metalized or metallized non-metallic substrate carriers, it is currently known, particularly in micro-optoelectronic devices, that backside ungrounded non-metallized semiconductor chips be deposited on conductive substrates by conductive adhesives, this compound having resistive conductivity shows. A disadvantage of this procedure proves that especially at temperature loads of the semiconductor devices, especially by diffusion processes on the bonded non-metallized semiconductor backside significant deterioration d (electrical properties, especially the ohmic behavior occur that lead to a significant proportion of failure devices. At present, there is no known method for increasing the yield of chip-bonded, wirebound and enveloped semiconductor bodies, preferably Si radiation receivers without backside metallization, at this stage of manufacture. The known technology at z. B. Ge-tip diodes for producing a characteristic semiconductor structure, does not improve the ohmic contact behavior and thus has no relation to the problem of technology for the production of chip-bonded semiconductor devices. Object of the invention The aim of the invention is to provide a method for increasing the yield of chip-bonded semiconductor devices with low-resistance contact behavior. Explanation of the essence of the invention The invention has for its object to provide a method for improving the ohmic contact behavior of chip-bonded semiconductor body. According to the invention, this object is achieved in that chip-bonded, wire-bonded and enveloped semiconductor body, preferably Si radiation receiver without backside metallization, a targeted optionally one or more times electrical pulse stress are subjected, the stress is adjusted by pulse height duty cycle and pulse width. In the treatment of transistors with the method according to the invention, the electrical pulse is directed so that a positive potential is applied to the emitter. embodiment The invention will be explained in more detail below using an exemplary embodiment. For the treatment according to the invention Si phototransistors were used in plastumhüllter carrier strip type. The assembly was carried out by chip bonding the non-metallized backside with silver-containing epoxy resin adhesive and a Golddrahtbondung and Klarplastumhüllung.