MOCVD Equipment Characteristics by Maker

MOCVD Equipment Characteristics by Maker

08/04/2010, Cathy

1. Overview

LED epi wafer growth equipments include LPE, VPE, MOCVD, MBE, and ALE. The MOCVD with excellent production capacity and reproductivity is used the most widely in the current market. Major MOCVD equipment makers are Aixtron (Germany), Veeco (U.S.), and Taiyo Nippon Sanso (Japan).

Characteristics of equipment are divided by reactor type, nozzle position, wafer rotation, and gas inlet type. Detailed descriptions are as follows.

Aixtron currently employs a horizontal triple injection type. Source gases come out of a nozzle in the center of reactor and are deposited on a substrate. Veeco employs a vertical type of which gasses come out of the grid with small holes, flow downward, and are deposited on a substrate. Tomas Swan (bought out by Aixtron) employs a vertical type, but its reactor is a shower head type. It easily maintains the laminar gas flow due to close distance in between susceptor. Taiyo Nippon Sanso employs GaN high growth ratio and room pressure growth method. It has a gas inlet at the bottom.

[Table 1. Reactor line-up of the MOCVD makers]

Although it is not introduced here, there are also company's independently manufactured MOCVDs. Advanced makers like Nichia, Toyota Gosei, and Cree use these independently manufactured equipments. In particular, Nichia, the world's top LED chip maker, has extremely high dependency on the independently manufactured equipment as there are several hundred units. However, we will exclude the independently manufactured equipments and only discuss the MOCVD equipment characteristics by global maker in this column.

2. Aixtron 2.1. G series

Aixtron's MOCVD is characteristic due to horizontal planetary reactor, closed coupled showerhead, and hot-well reactor technologies.

First, the planetary reactor technology was developed by Philips and Aixtron owns a license over the technology. This system employs a horizontal laminar flow reactor to enable an extremely delicate growth speed of heterojunction and monolayer level. In addition, the system employs a special reactor in-valve and unique multiple substrate carrier rotation called gas foil rotation (GFR).

The reactor is heated up by infrared ray (850?é) or induction (1200-1700?é, SiC growth). Key reactor products are illustrated in the following table. Aixtron owns MOCVDs which can manufacture 60 sheets of 2\GaN. They are widely used for 4\

[Table 2. G Series of Aixtron]

[Fig.1. AIX2800G4 HT 42 x 2\

Source: Aixtron

2.2. CRIUS

Aixtron has bought out England based Tomas Swan in 1999 and sells Tomas Swan's MOCVD reactors as they are. They are CRIUS models using the closed coupled showerhead (CCS). The CSS is recognized as an indisputable method upon evenness and scalability. It is employed in Aixtron's (formal Tomas Swan) multiple wafer reactors.

Reagents flow into the reactor through a water-cooled showerhead surface extending the overall deposition area. The showerhead is close to substrates and is divided right on top of spot where precursors are injected to the substrates through multiple small tubes.

Reagents are injected within a reactor chamber through separated orifices inside the water-cooled showerhead injector and produce very even reactor gas distributions. Substrates are located on top of rotating susceptor and operate resistive heating. In addition, a three-zone heater is employed in order to offer an even temperature all over the susceptor.

[Table 3. CCS Reactor Series]

[Fig.2. Available susceptor configurations of CCS reactor]

Source: Aixtron

3. Veeco

Veeco is a U.S. based MOCVD maker which has bought out Emcore. The company began the compound semiconductor epi growth business and manufactures electronic device-use MBE as well. Veeco uses a grid type reactor and employs a method to evenly inject gasses. It shows excellent equipment characteristics, easy and rapid maintenance, and run-to-run reproductivity that it is widely used in production equipment. As of now, K465(45X2%use.

[Table 4. Veeco's Reactor line-up]