JPH02301166A - Structure of photodiode - Google Patents

Abstract

PURPOSE:To enable detecting light output to a narrow section such as the etching end face groove of a semiconductor laser wafer by making a photodiode having a mesa-shaped light receiving face in stripe form. CONSTITUTION:An incident light 9 entering parallel to an S I-Inp substrate 11 is taken in through a light receiving face on the side face of a stripe-form mesa, converted into a current, and taken out to the outside through a p- electrode 7 and an n-electrode 8. The stripe-form mesa is for example several to ten odd micron wide and ten to several dozens of micro high, therefore, the stripe-form light receiving face can be inserted into an etching end face groove 22 formed in a semiconductor laser wafer 20 to receive light output 23 from an emitter region 21 and the light output characteristic of a semiconductor laser or an OEIC can be measured in the wafer state.

Description

[Detailed description of the invention] [Industrial application field] This statement is about photodiodes.

[Conventional technology]

FIG. 3 is a sectional view showing the structure 51 of a conventional potosuiode. In the figure, +Il is an n-type np substrate, (2) is an n-type np buffer layer, and (31 is a 1-InGaAs layer).

+41 n n-InGaAs layer, 151ij 81
N film, 161 is p diffusion region, (]) is p electrode, (8)
is the n-electrode, and (9) is the incident light.

Next, the operation will be explained. The incident light (9) that entered the light receiving surface on the p-10 diffusion region 16+ is converted into a current by the 1-1nGaAej stage 131, and the p-electrode +71, the i-electrode (
8) It is taken out from.

[Problem to be solved by the invention]

Since the conventional photodiode has the above structure,
Since it can only receive light incident on the wafer surface from a normal direction, it is not suitable for receiving light from the laser source in a narrow space such as the end face groove formed by laser wafer etching. The problem is Kametsu.

This invention was made to solve the above-mentioned problems, and is a photodiode fla that can detect incident light in a narrow space of several micrometers to several 10 micrometers.
The purpose is to

[Means to solve the problem]

The structure of the photodiode according to the present invention is such that a semiconductor substrate is formed into a striped mesa, and p- and n-type impurities are implanted on both sides of the mesa by diffusion or the like.
structure, with p1L poles and n
Each electrode is formed separately.

[Effect]

The structure of the photodiode according to the present invention includes a striped mesa p-1- formed parallel to a semiconductor substrate,
n Due to the structure, does the incident light become parallel to the semiconductor substrate?
It is also possible to receive light even in a narrow space such as an etched end face groove of a semiconductor laser wafer.

〔Example〕

A practical example of this invention will be described below.

FIG. 1 is a sectional view showing the structure of a photodiode, and FIG. 2 is a sectional view showing the photodiode shown in FIG. 1 mounted on a semiconductor laser wafer VC.

In the figure, 16) to i91 ij are the same as those shown in the conventional example of FIG. 3, so their explanation will be omitted.

true S, engineering (semi-insulating) engineering np group 1&, [2) Hl
-InGaA11 layer, bet is n diffusion region, Q41 is 1-
(4) Semiconductor laser (or C) K (C) Next, the structure and operation will be explained.

In FIG. 1, a 1-InGaAa layer a21 formed in a hash drive-shaped mesa is formed on the S, AEN np substrate qv, and p- and n-type impurities are diffused on the left and right side surfaces, and the S, AEN np substrate up It has a p-1-n structure parallel to the . In addition, the p- and n-type impurities are also diffused onto the wafer surfaces on the left and right sides of the striped mesa, and the V
Cp 1! A pole; 7) and an n-electrode (8) are respectively formed.

S, I - Incident light incident parallel to the np substrate dυ (
9) is taken in from the light-receiving surface on the side surface of the striped mesa, converted into a current VC, and sent to the p-electrode 171. n-electrode (8)
taken out to the outside.

The width of this striped mesa is, for example, several μm% IO
Since the height is several μm and the height is 10 to several 1011 m, a striped light-receiving surface is pushed into the etched end face groove formed in the semiconductor laser wafer garden as shown in FIG.
It is possible to receive the optical output 8 from the light emitting region 211, and the semiconductor laser or 01! The optical output characteristics of i-C can be measured.

In the above embodiment, the 'S, I-Engineering np substrate α1J is used, but the present invention can also be applied to photodiodes using other materials such as 1, 81, and the like. Further, although the n- and p-type impurities are implanted by diffusion, methods such as ion implantation may also be used.

〔Effect of the invention〕

As described above, according to the present invention, by adopting a photodiode structure having a striped mesa-type light-receiving surface,
The optical output of a narrow portion such as an etched end face groove of a semiconductor laser wafer can be detected, and the optical output characteristics of a semiconductor laser or 01[i-C can be measured in the wafer state.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a photodiode showing an embodiment of the present invention gAJ, Fig. 2 is a sectional view showing the photodiode of Fig. 1 mounted on a semiconductor laser wafer, and Fig. 8 is a sectional view of a conventional photodiode. It is a diagram. In the figure, (6) is the p ten-extension region, (71 is the p electrode, (
8) is an n-electrode, (9) is an incident light, 几 is S, AEN Np substrate, (121rii-InGjAs layer, (13Hjn diffusion region), 0mo is the same reference numeral indicates the same or equivalent part in the figure. .

Claims (1)

[Claims] The surface of the semiconductor substrate is formed into a striped mesa, a p-type impurity is mixed into the semiconductor substrate on one side of the mesa including one side of the mesa, and the mesa including the other side of the mesa is mixed with a p-type impurity. An n-type impurity is mixed into the semiconductor substrate on the other side to a depth that does not reach the p-type impurity mixed into the mesa, and a p-electrode and an n-electrode are respectively formed on the semiconductor substrate excluding the mesa. A photodiode structure characterized by: