Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/53—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone involving the removal of at least part of the materials of the treated article, e.g. etching, drying of hardened concrete
  • C04B41/5338—Etching
  • C04B41/5361—Etching with molten material
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices

Definitions

• This invention relates to a method of etching silicon carbide.
• etching technique In the fabrication of semiconductor elements, such as diodes, transistors or similar components, extensive use is made of the etching technique since like hardly any other material processing technique it makes possible the processing of small and very small bodies in a simple manner.
• a particular advantage of this technique resides in the fact that, by using etchants reacting exclusively or preferably with certain given materials, it is possible to effect a zone selection when bodies consisting dilferent substances or masks consisting of suitable substances are employed.
• etchants and etching techniques For the numerous semiconductor substances that have been disclosed so far and for the various problems arising in processing them, a large variety of etchants and etching techniques have been provided with which it has been possible to obtain optimum results in the individual fields.
• this invention provides a method of etching silicon carbide in which the bodies or surfaces to be etched, after having first been lapped by mechanical means to a roughness of preferably below 1 micron, cleaned by ultrasonic treatment, washed with HFHNO and rinsed with aqua destillata and alcohol, are placed into a melt consisting of Na O and NaNO
• An especially advantageous temperature range has proved to be that between 400 C. and 600 C.
• a 1:1 mixture ratio of the said substance has shown to be favorable, but other mixture ratios are also possible which for special applications may in certain circumstances deviate greatly from the 1:1 ratio.
• the silicon carbide bodies etched by this technique are eroded symmetrically and exhibit perfectly planar surfaces.
• a melt consisting essentially of sodium peroxide and sodium nitrite; the weight ratio between the sodium peroxide and sodium nitrite being on the order of 1 to 1; and maintaining contact between said surface and said melt until the desired amount of etching has taken place; said melt being maintained during the etching step at a temperature between about 400 C. and 600 C.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Weting (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7202205

Family Applications (1)

Country Status (5)

Cited By (8)

• 1964
  • 1964-03-06 DE DEJ25392A patent/DE1242972B/de active Pending
• 1965
  • 1965-02-12 GB GB4795/65A patent/GB1023749A/en not_active Expired
  • 1965-02-23 AT AT159865A patent/AT251651B/de active
  • 1965-03-03 US US436918A patent/US3421956A/en not_active Expired - Lifetime
  • 1965-03-03 FR FR7738A patent/FR1439074A/fr not_active Expired

Non-Patent Citations (1)

Also Published As

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