Jan Czochralski
Encyclopedia
Jan Czochralski was a Polish
chemist
who invented the Czochralski process
, which is used to grow single crystal
s and is used in the production of semiconductor
wafers.
Czochralski was born in Kcynia
, then in the Prussia
n Province of Pomerania. Around 1900 he moved to Berlin
, where he worked at a pharmacy. He was educated at Charlottenburg Polytechnic in Berlin, where he specialized in metal chemistry. Czochralski began working as an engineer
for Allgemeine Elektrizitäts Gesellschaft (AEG) in 1907.
He discovered the Czochralski method in 1916, when he accidentally dipped his pen into a crucible of molten tin rather than his inkwell
. He immediately pulled his pen out to discover that a thin thread of solidified metal was hanging from the nib
. The nib was replaced by a capillary, and Czochralski verified that the crystallized metal was a single crystal. The experiments of Czochralski produced single crystals that were a millimeter in diameter and up to 150 centimeters long. Czochralski published a paper on his discovery in 1918 in the Zeitschrift für Physikalische Chemie
, a German chemistry journal, under the title "Ein neues Verfahren zur Messung der Kristallisationsgeschwindigkeit der Metalle" [A new method for the measurement of the crystallization rate of metals], since the method was at that time used for measuring the crystallization rate of metals such as tin
, zinc
and lead
. In 1950, Americans Gordon K. Teal
and J.B. Little from Bell Labs
used this method to grow single germanium
crystals, which began its use in producing suitable semiconductors.
In 1917, Czochralski organized the research laboratory "Metallbank und Metallurgische Gesellschaft", which he directed until 1928. In 1919 he was one of the founding members of the German Society for Metals Science (Deutsche Gesellschaft für Metallkunde), of which he was president until 1925. In 1928, at the request of the president of Poland, Ignacy Mościcki
, he moved to Poland and became the Professor of Metallurgy and Metal Research at the Chemistry Department of the Warsaw University of Technology
.
During World War II
he was one of the engineers behind the development and construction of the R wz. 42 hand grenade
, better known as Sidolówka, for the Armia Krajowa
. After World War II he was stripped of his professorship due to his involvement with Germany during the war, although he was later cleared of any wrongdoing by a Polish court
. He returned to his native town of Kcynia where he ran a small cosmetics and household chemicals firm until his death in 1953.
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
chemist
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
who invented the Czochralski process
Czochralski process
The Czochralski process is a method of crystal growth used to obtain single crystals of semiconductors , metals , salts, and synthetic gemstones...
, which is used to grow single crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s and is used in the production of semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
wafers.
Czochralski was born in Kcynia
Kcynia
Kcynia is a town in Nakło County, Kuyavian-Pomeranian Voivodeship, Poland, with 4,712 inhabitants .Kcynia is the birthplace of Jan Czochralski....
, then in the Prussia
Prussia
Prussia was a German kingdom and historic state originating out of the Duchy of Prussia and the Margraviate of Brandenburg. For centuries, the House of Hohenzollern ruled Prussia, successfully expanding its size by way of an unusually well-organized and effective army. Prussia shaped the history...
n Province of Pomerania. Around 1900 he moved to Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
, where he worked at a pharmacy. He was educated at Charlottenburg Polytechnic in Berlin, where he specialized in metal chemistry. Czochralski began working as an engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...
for Allgemeine Elektrizitäts Gesellschaft (AEG) in 1907.
He discovered the Czochralski method in 1916, when he accidentally dipped his pen into a crucible of molten tin rather than his inkwell
Inkwell
An inkwell is a small jar or container, often made of glass, porcelain, silver, brass, or pewter, used for holding ink in a place convenient for the person who is writing...
. He immediately pulled his pen out to discover that a thin thread of solidified metal was hanging from the nib
Nib (pen)
A nib is the part of a quill, dip pen or fountain pen which comes into contact with the writing surface in order to deposit ink. Different types of nibs vary in their purpose, shape and size, as well as the material they are made from.-Quill:...
. The nib was replaced by a capillary, and Czochralski verified that the crystallized metal was a single crystal. The experiments of Czochralski produced single crystals that were a millimeter in diameter and up to 150 centimeters long. Czochralski published a paper on his discovery in 1918 in the Zeitschrift für Physikalische Chemie
Zeitschrift für Physikalische Chemie
Zeitschrift für Physikalische Chemie is a physical chemistry journal published in Germany. Its name literally means "Journal of Physical Chemistry", but its official English-language subtitle is "International journal of research in physical chemistry and chemical physics". Its emphasis is on...
, a German chemistry journal, under the title "Ein neues Verfahren zur Messung der Kristallisationsgeschwindigkeit der Metalle" [A new method for the measurement of the crystallization rate of metals], since the method was at that time used for measuring the crystallization rate of metals such as tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
, zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
and lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
. In 1950, Americans Gordon K. Teal
Gordon K. Teal
Gordon Kidd Teal invented a method of applying the Czochralski method to produce extremely pure germanium single crystals used in making greatly improved transistors. He, together with Morgan Sparks invented a modification of the process that produced the configuration necessary for the...
and J.B. Little from Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
used this method to grow single germanium
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. The isolated element is a semiconductor, with an appearance most similar to elemental silicon....
crystals, which began its use in producing suitable semiconductors.
In 1917, Czochralski organized the research laboratory "Metallbank und Metallurgische Gesellschaft", which he directed until 1928. In 1919 he was one of the founding members of the German Society for Metals Science (Deutsche Gesellschaft für Metallkunde), of which he was president until 1925. In 1928, at the request of the president of Poland, Ignacy Mościcki
Ignacy Moscicki
Ignacy Mościcki was a Polish chemist, politician, and President of Poland . He was the longest-serving President of Poland .-Life:...
, he moved to Poland and became the Professor of Metallurgy and Metal Research at the Chemistry Department of the Warsaw University of Technology
Warsaw University of Technology
The Warsaw University of Technology is one of the leading institutes of technology in Poland, and one of the largest in Central Europe. It employs 2,453 teaching faculty, with 357 professors . The student body numbers 36,156 , mostly full-time. There are 17 faculties covering almost all fields of...
.
During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
he was one of the engineers behind the development and construction of the R wz. 42 hand grenade
Hand grenade
A hand grenade is any small bomb that can be thrown by hand. Hand grenades are classified into three categories, explosive grenades, chemical and gas grenades. Explosive grenades are the most commonly used in modern warfare, and are designed to detonate after impact or after a set amount of time...
, better known as Sidolówka, for the Armia Krajowa
Armia Krajowa
The Armia Krajowa , or Home Army, was the dominant Polish resistance movement in World War II German-occupied Poland. It was formed in February 1942 from the Związek Walki Zbrojnej . Over the next two years, it absorbed most other Polish underground forces...
. After World War II he was stripped of his professorship due to his involvement with Germany during the war, although he was later cleared of any wrongdoing by a Polish court
Court
A court is a form of tribunal, often a governmental institution, with the authority to adjudicate legal disputes between parties and carry out the administration of justice in civil, criminal, and administrative matters in accordance with the rule of law...
. He returned to his native town of Kcynia where he ran a small cosmetics and household chemicals firm until his death in 1953.
External links
- http://www.itme.edu.pl/czochralski.htm
- http://www.tf.uni-kiel.de/matwis/amat/elmat_en/kap_6/advanced/t6_1_4.html
- http://www.ptwk.org.pl/php/patron.php?p=eng,pa