JPH07105406B2 - Manufacturing method of semiconductor device - Google Patents

Description

1. Technical Field of the Invention The present invention relates to a method for bonding an optical semiconductor chip to a heat sink or a substrate at a predetermined position with high accuracy.

(2) Background of technology Optical components such as PINs and LDs are monolithically integrated on optical semiconductor chips such as optical integrated circuits. In order to efficiently couple these optical components and the optical fiber or the like outside, it is necessary to accurately adjust the relative positions of the optical component and the optical fiber or the like. In the electrical LSI, signal input
The output can be bonded to the outside by bonding a gold wire to the chip, but for the input and output of light to the optical integrated circuit, it is necessary to bring the optical fiber etc. directly close to the optical components on the chip, so chip bonding with high position accuracy is very It will be an important technology.

(3) Conventional Technology and Problems Conventionally, the degree of integration of optical integrated circuits is low, and they are not in mass production.

Therefore, after such a chip is bonded to a heat sink or the like, the position of an external optical fiber is adjusted on a jig and then mounted.

When an optical integrated circuit chip is cut out from a wafer, the cut-out surface cannot always be placed in a fixed positional relationship with the optical components on the chip. (The chip cutting accuracy is not good in principle.) Because the chip cutting accuracy is poor, the PIN + LD, which are optical components on the integrated circuit, are not always in the specified position from the cutting surface, and an error of several + μm must be avoided. Absent.
On the other hand, it is extremely difficult to accurately determine the position of the optical component on the chip because it is small and integrated, and there is a possibility that it deteriorates when irradiated with laser light as the probe light.

FIG. 1 shows a conventional cutout without steps. For example, a cutout surface 2 of the cutout optical semiconductor chip 1, a component row of optical components 3 such as PIN and LD, and an integrated circuit 3 '.
And are not parallel. When component mounting or chip bonding is attempted by automatic control, if a reference signal is taken out by applying a laser beam or the like to the cutout surface 2, an error occurs with respect to the position of the optical component 3.

(4) Object of the Invention The present invention provides a high-position-accuracy bonding method for an optical integrated circuit chip in which a positional relationship with an optical component is accurately formed around the chip by etching and the step is used in chip bonding. To do.

(5) Structure of the Invention The present invention is the same photolithography process as the manufacturing process of the optical component and the optical integrated circuit in a region other than the optical component and the optical integrated circuit on the chip on which the optical component and the optical integrated circuit are formed. A step of forming a chip bonding positioning pattern determined by 1., a step of cutting a chip so as to include the positioning pattern, and a step of chip bonding using the pattern as a reference position. .

The present invention forms a step around the chip by plasma etching (RIE) or chemical etching. The position accuracy of the step from the optical component is determined by the same photosonography process as the integrated circuit fabrication process, and regardless of the cutting accuracy, the position of the optical integrated circuit chip can be determined by irradiating the stepped part with collimated laser light. Can be read accurately. By automatically controlling the external mounting jig based on the read signal, the accuracy of the mounting position on the heat sink or the substrate can be made accurate.

(6) Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings.

According to the present invention, before cutting a wafer on which an optical component and an optical integrated circuit are manufactured as an optical semiconductor chip, the periphery of the chip is etched to form a certain step between the chip surface and the periphery of the chip on which the optical component and the optical integrated circuit are formed. . Since this step is formed by the same photolithography process as the manufacturing process of the optical component and the optical integrated circuit, the relative positional relationship with the optical component, the optical integrated circuit and the like is very high. After that, the etched portion can be cut out with relatively low precision, and when the chip bonding is performed on the heat sink or the substrate, the stepped portion positioned with high precision is used.

FIG. 2 shows a chip having a step 4 in which the positional relationship with the optical component 3 is made constant by patterning after removing the drawbacks in the conventional automatic control mounting. You can mount it while looking at this step from above, but
If the mirror surface can be created by RIE (plasma reactive etching), a precise reference signal can be taken out by applying a laser beam to the step surface, and the mounting position accuracy can be improved.

FIG. 3 is an enlarged view of the stepped portion, where (a) is
RIE, (b) shows a forward mesa type 4'and a reverse mesa type 4 "by chemical etching.

In this embodiment, an example in which a step is formed by etching is given. However, when an automatic control mounting jig capable of detecting movement / rotation of a pattern of a predetermined size shape as shown in FIG. If a film 5 having a particularly high reflectance is vapor-deposited around the circuit chip 1 as shown in FIG. 4, the transfer can be detected by applying collimated light to the film.

Also, with such a mounting jig, the fourth jig that can be used for position confirmation
It goes without saying that it is possible to use patterns other than the figures.

(7) Effects of the Invention A step having a fixed positional relationship is formed around the chip, and while observing the step, the step is brought to a predetermined position with respect to the heat sink and the substrate, and the bonding is performed.

According to the present invention, the position of an optical component in an optical integrated circuit can be accurately detected, so that the position can be accurately given when a chip is automatically mounted or bonded on a heat sink or a substrate.

As a result, coupling loss at the time of inputting / outputting light is reduced, which is effective for fully automatic mounting of optical components.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a conventional method, FIG. 2 is a diagram for explaining the present invention, FIG. 3 is an enlarged diagram of a step portion, and FIG. 4 is a diagram for explaining another embodiment of the present invention. 1: Chip, 2: Chip cutout surface, 3: Optical component, 3 ′: Integrated circuit, 4,
4 ′, 4 ″: step, 5: film with high reflectance.

Claims (1)

[Claims] 1. An optical component, the optical component on a chip on which an optical integrated circuit is formed, and the optical component on an area other than the optical integrated circuit.
A step of forming a chip bonding positioning pattern determined by the same photolithography process as the manufacturing process of the optical integrated circuit; a step of cutting the chip so as to include the positioning pattern; and a chip using the pattern as a reference position. A method for manufacturing a semiconductor device, which comprises a step of bonding.