EXHIBIT 10.17

                                                           DUE:  March 31, 1999
                                 PROMISSORY NOTE

                                  SEMITOOL, INC

$10,000,000.00                                        Dated: September 29, 1997
                                                            Spokane, Washington

         SEMITOOL, INC, a MONTANA corporation ("Maker") unconditionally promises
to pay to the order of Bank of America  National Trust and Savings  Association,
doing  business as SEAFIRST  BANK  ("Bank"),  at its Spokane  Wholesale  Banking
office,  on or before  March 31,  1999,  in  immediately  available  funds,  the
principal sum of Ten Million and  no/100ths  Dollars  ($10,000,000.00),  or such
lesser sum as may be advanced hereunder. Maker further agrees to pay interest on
the daily unpaid  principal  balance,  in arrears on the 31st day of each month,
beginning  the  31st  day of  October,  1997,  in  accordance  with  the  terms,
conditions,  and  definitions  of  Exhibit A  attached,  which are  incorporated
herein.  Also  incorporated  herein is  Exhibit  1  attached  hereto,  regarding
prepayment fees.

         All advances under this Note, all conversions between the interest rate
options,  and all  payments of  principal  and  interest  may be  reflected on a
schedule or a computer-generated statement which shall become a part hereof. All
unpaid  principal and accrued but unpaid  interest under this Note shall be paid
in full on March 31, 1999.

         Bank is authorized to  automatically  debit each required  installment
of interest from Borrower's  checking  account number 13629803 at Bank, or such 
other deposit account at Bank as Borrower may authorize in the future.

         A Commitment Fee of .25 percentage  points of the unused portion of the
commitment shall be collected quarterly.

         If all or any portion of the  principal  amount or any  installment  of
interest  is not paid when due,  interest  shall  accrue,  at the  option of the
holder of this Note, from the date of default at a floating rate per annum three
percent (3%) above the Reference  Rate, as the Reference Rate may vary from time
to time, and the entire unpaid principal amount of this Note,  together with all
accrued interest,  shall become immediately due and payable at the option of the
holder hereof.

         Advances  under  this  Note may be made by Bank at the oral or  written
request of Raymon F Thompson,  Larry Viano, John Sullivan,  Rebecca  Hand-Smith,
any one acting  alone,  who are  authorized  to request  advances and direct the
disposition  of any such advances until written notice of the revocation of such
authority is received by Bank at its office  indicated  above.  Any such advance
shall be conclusively  presumed to have been made to or for the benefit of Maker
when made in accordance with such requests and directions, or when said advances
are deposited to the credit of an account of Maker with Bank,  regardless of the
fact that persons  other than those  authorized  under this  paragraph  may have
authority to draw against such account.

         Maker  hereby  waives  presentment,  demand,  protest,  and  notice  of
dishonor  hereof.  Each party signing or endorsing  this Note signs as maker and
principal, and not as guarantor, surety, or accommodation party; and is estopped
from asserting any defense based on any capacity other than maker or principal.

         This Note shall be governed by and  construed  in  accordance  with the
laws of the State of Washington.

         ORAL AGREEMENTS OR ORAL COMMITMENTS TO LOAN MONEY, TO EXTEND CREDIT, OR
TO  FORBEAR  FROM  ENFORCING  REPAYMENT  OF A DEBT  ARE  NOT  ENFORCEABLE  UNDER
WASHINGTON LAW.

                                                   SEMITOOL, INC



                                                   By:   /s/ Raymon F. Thompson
                                                       ------------------------
                                                         Raymon F Thompson

                                                   Its:  President
                                                       ------------------------

<PAGE>



                                    EXHIBIT A
                               INTEREST PROVISIONS

                                    ARTICLE 1
                                   Definitions

         All terms defined below shall have the meaning indicated:
         1.1  Adjusted  LIBOR  Rate  shall  mean for any day that per annum rate
equal to the sum of (a) a margin of 2.00%,  (b) the Assessment Rate, and (c) the
quotient of (i) the LIBOR Rate as determined  for such day,  divided by (ii) the
Reserve Adjustment.  The Adjusted LIBOR Rate shall change with any change in the
LIBOR Rate on the first day of each Interest Period and on the effective date of
any change in the Assessment Rate or Reserve Adjustment.
         1.2 Advances  shall mean the  disbursement  of loan proceeds  under the
Note.
         1.3  Assessment  Rate  shall  mean  as of any day  the  minimum  annual
percentage rate established by the Federal Deposit Insurance Corporation (or any
successor)  for the  assessment  due from members of the Bank Insurance Fund (or
any successor) in effect for the assessment  period during which said day occurs
based on deposits  maintained at such members'  offices  located  outside of the
United States.  In the event of a retroactive  reduction in the Assessment  Rate
after a commencement of any Interest Period, Bank shall not retroactively adjust
as to such Interest  Period any interest rate  calculated  using the  Assessment
Rate.
         1.4      Available Amounts shall mean $10,000,000.00 less the 
outstanding principal balance of the Note.
         1.5      Bank shall mean the holder of the Note.
         1.6      Borrower shall mean the maker of the Note.
         1.7      Business Day shall mean any day other than a Saturday, Sunday,
or other day on which commercial banks in Seattle,  Washington,  are authorized 
or required by law to close.
         1.8  Commencement  Date shall mean the first day of any Interest Period
as  requested by  Borrower.
         1.9  Floating  Rate Loans shall mean those portions of principal of the
Note accruing  interest at the Floating Rate.
         1.10  Floating Rate shall mean the Reference Rate plus 0.00% per annum.
         1.11  Interest  Period shall mean the period  commencing on the date of
any advance at or  conversion  to an Adjusted  LIBOR Rate and ending on any date
thereafter as selected by Borrower, subject to the restrictions of Section 0. If
any Interest Period would end on a day which is not a Business Day, the Interest
Period shall be extended to the next succeeding Business Day.
         1.12 LIBOR Rate shall mean for any Interest  Period the per annum rate,
calculated  on the basis of actual  number  of days  elapsed  over a year of 360
days,  for U.S.  Dollar  deposits  for a period  equal  to the  Interest  Period
appearing on the display  designated as "Page 3750" on the Telerate  Service (or
such other page on that service or such other service  designated by the British
Banker's  Association for the display of that Association's  Interest Settlement
Rates for U.S. Dollar deposits) as of 11:00 a.m.,  London time, on the day which
is two London  Banking  Days prior to the first day of the Interest  Period.  If
there is no period equal to the Interest  Period on the display,  the LIBOR Rate
shall be determined by straight-line interpolation to the nearest month (or week
or day if  expressed  in weeks or days)  corresponding  to the  Interest  Period
between the two nearest neighboring periods on the display.
         1.13     LIBOR Rate Loans shall mean those portions of principal of the
Note accruing interest at the Adjusted LIBOR Rate.
         1.14     London  Banking  Day shall mean any day other than a Saturday,
Sunday,  or other day on which  commercial  banks in London,  England,  are 
authorized  or required by law to close.
         1.15 Note  shall  mean the  promissory  note to which  this  exhibit is
attached.
         1.16 Reference Rate shall mean the rate of interest publicly  announced
from time to time by Bank in San Francisco, California, as its "Reference Rate."
The Reference Rate is set based on various  factors,  including Bank's costs and
desired return, general economic conditions, and other factors, and is used as a
reference  point for pricing some loans.  Bank may price loans to its  customers
at, above,  or below the Reference  Rate. Any change in the Reference Rate shall
take  effect at the  opening  of  business  on the day  specified  in the public
announcement of a change in the Reference Rate.
         1.17 Reserve  Adjustment  shall mean as of any day the remainder of one
minus that percentage  (expressed as a decimal) which is the highest of any such
percentages  established by the Board of Governors of the Federal Reserve System
(or any successor) for required reserves (including any emergency,  marginal, or
supplemental reserve requirement) regardless of the aggregate amount of deposits
with said member bank and without  benefit of any  possible  credit,  proration,
exemptions,  or offsets for time deposits established at offices of member banks
located outside of the United States or for eurocurrency liabilities, if any.
         1.18     Termination  Date shall mean March 31, 1999,  or such earlier 
date upon which Bank makes demand for payment in full under the Note based on a 
default under the Note.

                                    ARTICLE 2
                              Interest Rate Options

         2.1 Interest  Rates and Payment Date. The Note shall bear interest from
the date of Advance on the unpaid  principal  balance  outstanding  from time to
time at the Floating Rate or Adjusted LIBOR Rate as selected by Borrower and all
accrued interest shall be payable in arrears as provided in the Note.
         2.2  Procedure.  Borrower  may,  on any London  Banking  Day two London
Banking Days before a Commencement  Date, request Bank to give an Adjusted LIBOR
Rate quote for a specified loan amount and Interest Period. Bank will then quote
to Borrower the available  Adjusted  LIBOR Rate.  Borrower  shall have two hours
from the  time of the  quote to elect an  Adjusted  LIBOR  Rate by  giving  Bank
irrevocable notice of such election.
         2.3 Restrictions. Each Interest Period shall be one month or two months
or three months or six months or any other term  acceptable  to Bank in its sole
discretion.  In no event shall an Interest  Period extend beyond the Termination
Date. The minimum amount of a LIBOR Rate Loan shall be $250,000.
         2.4 Prepayments. If Borrower prepays all or any portion of a LIBOR Rate
Loan prior to the end of an Interest  Period,  there shall be due at the time of
any such  prepayment  the  Prepayment  Fee,  determined in accordance  with Form
51-6325 which is attached as Exhibit 1 to the Note.
         2.5 Reversion to Floating. The Note shall bear interest at the Floating
Rate unless an Adjusted LIBOR Rate is specifically  selected. At the termination
of any Interest Period each LIBOR Rate Loan shall revert to a Floating Rate Loan
unless Borrower directs otherwise pursuant to Section 0.
         2.6 Inability to  Participate  in Market.  If Bank in good faith cannot
participate  in the  Eurodollar  market  for  legal or  practical  reasons,  the
Adjusted LIBOR Rate shall cease to be an interest rate option. Bank shall notify
Borrower of and when it again becomes legal or practical to  participate  in the
Eurodollar  market,  at which time the Adjusted LIBOR Rate shall resume being an
interest rate option.
         2.7 Costs.  Borrower shall, as to LIBOR Rate Loans,  reimburse Bank for
all costs,  taxes,  and  expenses,  and defend  and hold Bank  harmless  for any
liabilities, which Bank may incur as a consequence of any changes in the cost of
participating  in,  or in the  laws or  regulations  affecting,  the  Eurodollar
market, including any additional reserve requirements, except to the extent such
costs are already  calculated  into the Adjusted LIBOR Rate. This covenant shall
survive the payment of the Note.
         2.8 Basis of Quotes.  Borrower acknowledges that Bank may or may not in
any particular case actually match-fund a LIBOR Rate Loan. FDIC assessments, and
Federal Reserve Board reserve requirements,  if any are assessed,  will be based
on Bank's best  estimates of its marginal cost for each of these items.  Whether
such  estimates  in fact  represent  the actual cost to Bank for any  particular
dollar or  Eurodollar  deposit or any LIBOR Rate Loan will  depend upon how Bank
actually  chooses to fund the LIBOR Rate Loan.  By electing  an  Adjusted  LIBOR
Rate,  Borrower  waives any right to object to Bank's means of  calculating  the
Adjusted LIBOR Rate quote accepted by Borrower.

                                    ARTICLE 3
                                    Advances

         3.1 Revolving Loan Facility.  Bank shall until the earlier of demand or
the Termination  Date make Advances to Borrower from time to time, to the extent
of the Available  Amounts,  with the aggregate  principal amount at any one time
outstanding  not to exceed  $10,000,000.00.  Borrower  may borrow,  prepay,  and
reborrow the principal of the Note in whole or in part.
         3.2 Procedure  for  Advances.  Borrower may borrow on any Business Day.
Borrower shall give Bank  irrevocable  notice  (written or oral)  specifying the
amount to be borrowed and the requested  borrowing  date. Bank must receive such
notice on or before 11:30 a.m., Seattle time, on the day borrowing is requested.
All Advances shall be  discretionary  to the extent  notification by Borrower is
given subsequent to that time.

                          Exhibit 1 -- PREPAYMENT FEES

         If the  principal  balance of this note is prepaid in whole or in part,
whether by voluntary prepayment,  operation of law, acceleration or otherwise, a
prepayment fee, in addition to any interest earned,  will be immediately payable
to the holder of this note.

         The amount of the prepayment fee depends on the following:

(1) The amount by which interest  reference  rates as defined below have changed
between  the time the loan is  prepaid  and either a) the time the loan was made
for fixed rate loans,  or b) the time the interest rate last changed  (repriced)
for variable rate loans.
(2) A prepayment fee factor (see  "Prepayment Fee Factor  Schedule" on reverse).
(3) The amount of principal prepaid.

If the proceeds from a CD or time deposit pledged to secure the loan are used to
prepay the loan resulting in payment of an early withdrawal  penalty for the CD,
a prepayment fee will not also be charged under the loan.

              Definition of Reference Rate for Variable Rate Loans

The  "Reference  Rate" used to represent  interest rate levels for variable rate
loans  shall be the index rate used to  determine  the rate on this loan  having
maturities  equivalent  to the  remaining  period to  interest  rate change date
(repricing)  of this loan  rounded  upward to the nearest  month.  The  "Initial
Reference  Rate" shall be the Reference Rate at the time of last repricing and a
new Initial Reference Rate shall be assigned at each subsequent  repricing.  The
"Final Reference Rate" shall be the Reference Rate at the time of prepayment.

                Definition of Reference Rate for Fixed Rate Loans

The "Reference Rate" used to represent  interest rate levels on fixed rate loans
shall be the bond  equivalent  yield of the average  U.S.  Treasury  rate having
maturities  equivalent to the remaining  period to maturity of this loan rounded
upward to the nearest month. The "Initial Reference Rate" shall be the Reference
Rate at the time the loan was made.  The  "Final  Reference  Rate"  shall be the
Reference Rate at time of prepayment.

The Reference  Rate shall be  interpolated  from the yields as displayed on Page
119 of the Dow Jones  Telerate  Service  (or such  other  page or service as may
replace that page or service for the purpose of displaying  rates  comparable to
said U.S. Treasury rates) on the day the loan was made (Initial  Reference Rate)
or the day of prepayment (Final Reference Rate).

An Initial  Reference  Rate of N/A % has been assigned to this loan to represent
interest rate levels at origination.

                          CALCULATION OF PREPAYMENT FEE

If the Initial Reference Rate is less than or equal to the Final Reference Rate,
there is no prepayment fee.

If the Initial  Reference  Rate is greater than the Final  Reference  Rate,  the
prepayment  fee shall be equal to the  difference  between the Initial and Final
Reference Rates (expressed as a decimal),  multiplied by the appropriate  factor
from the Prepayment Fee Factor  Schedule,  multiplied by the principal amount of
the loan being prepaid.

                      Example of Prepayment Fee Calculation

Variable Rate Loan: A non-amortizing  6-month LIBOR based loan with principal of
$250,000 is fully  prepaid  with 3 months  remaining  until next  interest  rate
change date  (repricing).  An Initial Reference Rate of 7.0% was assigned to the
loan at last  repricing.  The Final Reference Rate (as determined by the 3-month
LIBOR index) is 6.5%. Rates therefore have dropped 0.5% since last repricing and
a prepayment  fee applies.  A prepayment  fee factor of 0.31 is determined  from
Table 3 below and the prepayment fee is computed as follows:

        Prepayment Fee = (0.07 -- 0.065) x (0.31) x ($250,000) = $387.50

Fixed Rate Loan:  An  amortizing  loan with  remaining  principal of $250,000 is
fully prepaid with 24 months remaining until maturity. An Initial Reference Rate
of 9.0% was  assigned  to the loan when the loan was made.  The Final  Reference
Rate (as  determined by the current  24-month U.S.  Treasury rate on Page 119 of
Telerate) is 7.5%. Rates therefore have dropped 1.5% since the loan was made and
a prepayment  fee applies.  A prepayment  fee factor of 1.3 is  determined  from
Table 1 below and the prepayment fee is computed as follows:

         Prepayment Fee = (0.09 -- 0.075) x (1.3) x ($250,000) = $4,875
<TABLE>
<CAPTION>

                         PREPAYMENT FEE FACTOR SCHEDULE

                         TABLE I: FULLY AMORTIZING LOANS
Proportion of Remaining  PrincipalMonths Remaining To Maturity/Repricing1
Amount Being Prepaid
--------------------------------------------------------------------------------------------------------------------
<S>                <C>    <C>     <C>    <C>    <C>     <C>    <C>    <C>     <C>    <C>    <C>     <C>    <C>
                   0      3       6      9      12      24     36     48      60     84     120     240    360
--------------------------------------------------------------------------------------------------------------------
90-100%            0      .21     .36    .52    .67     1.3    1.9    2.5     3.1    4.3    5.9     10.3   13.1
60-89%             0      .24     .44    .63    .83     1.6    2.4    3.1     3.9    5.4    7.5     13.2   17.0
30-59%             0      .28     .53    .78    1.02    2.0    3.0    4.0     5.0    7.0    9.9     18.5   24,4
0-29%              0      .31     .63    .92    1.22    2.4    3.7    5.0     6.3    9.0    13.4    28.3   41.8
</TABLE>

<TABLE>
<CAPTION>

                 TABLE II: PARTIALLY AMORTIZING (BALLOON) LOANS
Proportion  of  Remaining  PrincipalMonths Remaining To Maturity/Repricing1
Amount Being Prepaid
--------------------------------------------------------------------------------------------------------------------
<S>                   <C>    <C>    <C>    <C>    <C>    <C>     <C>    <C>    <C>    <C>    <C>    <C>    <C>
                      0      3      6      9      12     24      36     48     60     84     120    240    360
--------------------------------------------------------------------------------------------------------------------
90-100%               0      .26    .49    .71    .94    1.8     2.7    3.4    4.2    5.6    7.4    11.6   14.0
60-89%                0      .30    .59    .86    1.15   2.2     3.3    4.3    5.3    7.1    9.4    15.0   18.1
30-59%                0      .31    .63    .95    1.27   2.6     3.9    5.3    6.6    9.1    12.6   21.2   26.2
0-29%                 0      .31    .63    .95    1.27   2.6     4.0    5.4    7.0    10.2   15.7   33.4   46.0
</TABLE>

<TABLE>
<CAPTION>

                 TABLE III: NONAMORTIZING (INTEREST ONLY) LOANS
Proportion  of  Remaining  PrincipalMonths Remaining To Maturity/Repricing1
Amount Being Prepaid
--------------------------------------------------------------------------------------------------------------------
<S>                   <C>    <C>    <C>    <C>    <C>    <C>     <C>    <C>    <C>    <C>    <C>    <C>    <C>
                      0      3      6      9      12     24      36     48     60     84     120    240    360
--------------------------------------------------------------------------------------------------------------------
0-100%                0      .31    .61    .91    1.21   2.3     3.4    4.4    5.3    6.9    8.9    13.0   14.8
</TABLE>


1  For   the   remaining   period   to   maturity/repricing   between   any  two
maturities/repricings  shown in the above  schedules,  interpolate  between  the
corresponding factors to the closest month.

The  holder  of this note is not  required  to  actually  reinvest  the  prepaid
principal in any U.S.  Government Treasury  Obligations,  or otherwise prove its
actual loss, as a condition to receiving a prepayment fee as calculated above.